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Sources
24
1 strong · 18 moderate · 5 weak

Studies and references cited across this article, graded by evidence strength.

Claims checked
82
48verified10partial24inconclusive

Inconclusive means the cited source neither confirms nor refutes the claim — a lower-confidence badge, not an error.

Generated
May 11, 2026 · pipeline-v5
Values approved
91/91 (100%)

Data points an editor reviewed and accepted for publication.

01

Value Provenance

Dosing

oraltrace

FieldPublishedAI ProposedConfidence
Threshold10 mg10 mglow
Low20–40 mg20–40 mglow
Common40–100 mg40–100 mglow
Strong100–200 mg100–200 mglow
Heavy200+ mg200+ mglow
Editorial

Values carried forward from existing DB seed data. Not verified by any published controlled human dose-response study. The original clinical tablet was 50 mg (ACS source), consistent with the common range. Clinical abuse populations report 1-15 tablets/day (50-750 mg; Shalaby 2023), consistent with the strong-to-heavy range. Threshold of 10 mg yields ~2.5 mg amphetamine equivalent. Dose ranges are class-inferred and historical — no controlled human dose study exists for fenethylline.

Reasoning

Values carried forward from existing DB seed data. Not verified by any published controlled human dose-response study. The original clinical tablet was 50 mg (ACS source), consistent with the common range. Clinical abuse populations report 1-15 tablets/day (50-750 mg; Shalaby 2023), consistent with the strong-to-heavy range. Threshold of 10 mg yields ~2.5 mg amphetamine equivalent. Dose ranges are class-inferred and historical — no controlled human dose study exists for fenethylline.

Evidence basis: community_consensus_large

Duration

oral

FieldPublishedAI ProposedConfidence
Onsettrace90–120 minutes90–120 minuteslow
Editorial

From existing DB seed data. Not verified by published human study. Plausible based on oral amphetamine absorption kinetics and the hydrochloride salt's water solubility.

Reasoning

From existing DB seed data. Not verified by published human study. Plausible based on oral amphetamine absorption kinetics and the hydrochloride salt's water solubility.

Evidence basis: community_consensus_large

Come uptrace30–60 minutes30–60 minuteslow
Editorial

No fenethylline-specific data. Estimated from amphetamine-class oral come-up duration (typically 30-60 min after onset). Structural analogy with amphetamine.

Reasoning

No fenethylline-specific data. Estimated from amphetamine-class oral come-up duration (typically 30-60 min after onset). Structural analogy with amphetamine.

Evidence basis: structural_analogy

Peaktrace1–2 hours1–2 hourslow
Editorial

No fenethylline-specific data. Estimated from amphetamine-class oral peak duration. Consistent with the 3-4 hour total duration in existing DB when accounting for onset, come-up, and offset phases.

Reasoning

No fenethylline-specific data. Estimated from amphetamine-class oral peak duration. Consistent with the 3-4 hour total duration in existing DB when accounting for onset, come-up, and offset phases.

Evidence basis: structural_analogy

Offsettrace1–2 hours1–2 hourslow
Editorial

No fenethylline-specific data. Estimated from amphetamine-class oral offset duration. Consistent with total duration of 3-4 hours.

Reasoning

No fenethylline-specific data. Estimated from amphetamine-class oral offset duration. Consistent with total duration of 3-4 hours.

Evidence basis: structural_analogy

Totaltrace3–4 hours3–4 hourslow
Editorial

From existing DB seed data. Not verified by published human study. Plausible based on oral amphetamine duration. Represents subjective experience duration excluding aftereffects.

Reasoning

From existing DB seed data. Not verified by published human study. Plausible based on oral amphetamine duration. Represents subjective experience duration excluding aftereffects.

Evidence basis: community_consensus_large

After effectstrace2–6 hours2–6 hourslow
Editorial

No fenethylline-specific data. Estimated from amphetamine metabolite half-life (10-13 hours) and the CYP2D6 inhibition feedback loop that prolongs theophylline action. Residual insomnia, irritability, and fatigue expected.

Reasoning

No fenethylline-specific data. Estimated from amphetamine metabolite half-life (10-13 hours) and the CYP2D6 inhibition feedback loop that prolongs theophylline action. Residual insomnia, irritability, and fatigue expected.

Evidence basis: structural_analogy

Safety

Toxicity Profiletrace

FieldPublishedAI ProposedConfidence
Acutemoderatemoderatelow
Chronicmoderatemoderatelow
Organs Affectedcardiovascular, neuropsychiatric, thermoregulatorycardiovascular, neuropsychiatric, thermoregulatorylow
Editorial

Moderate acute/chronic ratings are class-inferred from amphetamine pharmacology — no primary fenethylline toxicology study exists. Case reports document cardiovascular events (MI: Gokdemir 2019; Brugada: Gul 2023) at abuse doses. Rat models show QT prolongation (Shehata 2025). Psychiatric toxicity documented in 101-patient series (Shalaby 2023). Evidence is mixed between case reports, animal data, and class extrapolation — confidence is low.

Reasoning

Moderate acute/chronic ratings are class-inferred from amphetamine pharmacology — no primary fenethylline toxicology study exists. Case reports document cardiovascular events (MI: Gokdemir 2019; Brugada: Gul 2023) at abuse doses. Rat models show QT prolongation (Shehata 2025). Psychiatric toxicity documented in 101-patient series (Shalaby 2023). Evidence is mixed between case reports, animal data, and class extrapolation — confidence is low.

Evidence basis: published_case_series

Dependence Profiletrace

FieldPublishedAI ProposedConfidence
Physicallowlowlow
Psychologicalmoderatemoderatelow
Compulsive Redosingmoderatemoderatelow
Dose Escalationmoderatemoderatelow
Editorial

Dependence liability established by international scheduling rationale (Fong 2024), Saudi treatment population data (Katselou 2016), and qualitative withdrawal reports (Wazaify 2024). Physical dependence rated low (amphetamine-class physical withdrawal is typically mild); psychological dependence moderate based on documented compulsive use patterns. No controlled dependence study exists for fenethylline specifically.

Reasoning

Dependence liability established by international scheduling rationale (Fong 2024), Saudi treatment population data (Katselou 2016), and qualitative withdrawal reports (Wazaify 2024). Physical dependence rated low (amphetamine-class physical withdrawal is typically mild); psychological dependence moderate based on documented compulsive use patterns. No controlled dependence study exists for fenethylline specifically.

Evidence basis: community_consensus_large

Withdrawal Profiletrace

FieldPublishedAI ProposedConfidence
Severitymoderatemoderatelow
Symptomscrash/fatigue, depression, craving, sleep disturbance, irritability, anhedoniacrash/fatigue, depression, craving, sleep disturbance, irritability, anhedonialow
FatalNoNolow
Medical SupervisionNot requiredNot requiredlow
Editorial

No formal fenethylline-specific withdrawal characterization published. Qualitative reports from captagon users in Jordan describe crash/fatigue, depression, craving, and sleep disturbance (Wazaify 2024). Onset (12-24h), peak (2-4 days), and total duration (1-2 weeks) inferred from amphetamine-class withdrawal timelines. Severity rated moderate based on amphetamine analog.

Reasoning

No formal fenethylline-specific withdrawal characterization published. Qualitative reports from captagon users in Jordan describe crash/fatigue, depression, craving, and sleep disturbance (Wazaify 2024). Onset (12-24h), peak (2-4 days), and total duration (1-2 weeks) inferred from amphetamine-class withdrawal timelines. Severity rated moderate based on amphetamine analog.

Evidence basis: community_consensus_large

Tolerance Profiletrace

FieldPublishedAI ProposedConfidence
Buildupmoderatemoderatelow
Half-life5 days5 dayslow
Full Reset14 days14 dayslow
Cross-tolerancesamphetamine, methamphetamine, other amphetamine-type stimulantsamphetamine, methamphetamine, other amphetamine-type stimulantslow
Editorial

Tolerance buildup rate, half-life, and full reset values are entirely class-inferred from amphetamine. No controlled fenethylline tolerance data exist. Cross-tolerance with amphetamine-type stimulants expected based on shared TAAR1/DAT/NET mechanisms. Confidence is low — structural analogy only.

Reasoning

Tolerance buildup rate, half-life, and full reset values are entirely class-inferred from amphetamine. No controlled fenethylline tolerance data exist. Cross-tolerance with amphetamine-type stimulants expected based on shared TAAR1/DAT/NET mechanisms. Confidence is low — structural analogy only.

Evidence basis: structural_analogy

Effects & Profile

Contraindications

FieldPublishedAI ProposedConfidence
other MAOI use (current or within 14 days)traceabsoluteabsolutehigh
Editorial

Standard amphetamine-class absolute contraindication. No fenethylline-specific case data, but mechanism is well-established for the amphetamine metabolite. Class-level extrapolation.

Reasoning

Standard amphetamine-class absolute contraindication. No fenethylline-specific case data, but mechanism is well-established for the amphetamine metabolite. Class-level extrapolation.

cardiovascular Known Brugada syndrometraceabsoluteabsolutemedium
Editorial

Documented in case reports (Gul 2023) — fenethylline induces Brugada phenocopy. Pre-existing Brugada syndrome amplifies this risk to life-threatening levels.

Reasoning

Documented in case reports (Gul 2023) — fenethylline induces Brugada phenocopy. Pre-existing Brugada syndrome amplifies this risk to life-threatening levels.

cardiovascular Recent myocardial infarction or unstable anginatraceabsoluteabsolutemedium
Editorial

Case report documents MI in a young user (Gokdemir 2019). Amphetamine-class coronary vasospasm mechanism is well-established. Absolute contraindication in setting of recent MI or unstable angina.

Reasoning

Case report documents MI in a young user (Gokdemir 2019). Amphetamine-class coronary vasospasm mechanism is well-established. Absolute contraindication in setting of recent MI or unstable angina.

cardiovascular Cardiac conduction abnormalities or prolonged QT intervaltracerelativerelativemedium
Editorial

QT prolongation documented in animal models (Shehata 2025). Synergistic cardiotoxicity with azithromycin (a QT-prolonging drug) demonstrated in rats. Relative contraindication with medium confidence based on animal data.

Reasoning

QT prolongation documented in animal models (Shehata 2025). Synergistic cardiotoxicity with azithromycin (a QT-prolonging drug) demonstrated in rats. Relative contraindication with medium confidence based on animal data.

psychiatric Psychotic disorders or family history of schizophreniatracerelativerelativemedium
Editorial

Dose-dependent psychosis documented in clinical case series (Shalaby 2023). Hallucinations and psychosis caused US market withdrawal. First-degree family history of schizophrenia is a standard amphetamine-class risk factor.

Reasoning

Dose-dependent psychosis documented in clinical case series (Shalaby 2023). Hallucinations and psychosis caused US market withdrawal. First-degree family history of schizophrenia is a standard amphetamine-class risk factor.

cardiovascular Coronary artery diseasetracerelativerelativemedium
Editorial

Systematic review of ATS and ACS (Gresnigt 2023) establishes class-level cardiovascular risk. Fenethylline case report of MI in young user supports mechanism. Relative contraindication in CAD.

Reasoning

Systematic review of ATS and ACS (Gresnigt 2023) establishes class-level cardiovascular risk. Fenethylline case report of MI in young user supports mechanism. Relative contraindication in CAD.

hepatic Hepatic impairment affecting CYP2D6 or CYP1A2tracerelativerelativelow
Editorial

CYP2D6 and CYP1A2 involvement documented (Kraemer & Maurer 2002). Hepatic impairment would disrupt the metabolic feedback loop (amphetamine inhibition of CYP2D6 slowing theophylline clearance). Low confidence — no fenethylline-specific hepatic impairment data.

Reasoning

CYP2D6 and CYP1A2 involvement documented (Kraemer & Maurer 2002). Hepatic impairment would disrupt the metabolic feedback loop (amphetamine inhibition of CYP2D6 slowing theophylline clearance). Low confidence — no fenethylline-specific hepatic impairment data.

other Concurrent CYP2D6-metabolized drugs with narrow therapeutic indextracerelativerelativemedium
Editorial

CYP2D6 inhibition by amphetamine metabolite documented (Wu et al. 2019). Pharmacokinetic drug interaction risk is mechanistically established. Medium confidence.

Reasoning

CYP2D6 inhibition by amphetamine metabolite documented (Wu et al. 2019). Pharmacokinetic drug interaction risk is mechanistically established. Medium confidence.

pregnancy breastfeeding Pregnancy and lactationtracerelativerelativelow
Editorial

Class-level extrapolation from amphetamine. No fenethylline-specific data. Low confidence — structural analogy only.

Reasoning

Class-level extrapolation from amphetamine. No fenethylline-specific data. Low confidence — structural analogy only.

Timeline Phases

oral

FieldPublishedAI ProposedConfidence
Onsettrace5400–7200 sec(i=0.05)5400–7200 sec(i=0.05)low
Editorial

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Reasoning

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Evidence basis: structural_analogy

Come uptrace1800–3600 sec(i=0.35)1800–3600 sec(i=0.35)low
Editorial

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Reasoning

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Evidence basis: structural_analogy

Peaktrace3600–7200 sec(i=1.00)3600–7200 sec(i=1.00)low
Editorial

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Reasoning

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Evidence basis: structural_analogy

Resolutiontrace3600–7200 sec(i=0.30)3600–7200 sec(i=0.30)low
Editorial

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Reasoning

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Evidence basis: structural_analogy

Afterglowtrace7200–21600 sec(i=0.15)7200–21600 sec(i=0.15)low
Editorial

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Reasoning

No published human pharmacokinetic study characterizes fenethylline's temporal profile. Onset (90-120 min) and total (3-4 hours) from existing DB. Come-up, peak, and offset phases inferred from amphetamine-class oral timeline. Afterglow duration estimated from amphetamine metabolite half-life (10-13 hours) and CYP2D6 inhibition feedback loop. All phase durations are structural analogy from amphetamine.

Evidence basis: structural_analogy

Dose Tier Summaries

thresholdtrace
low

Minimal perceptible stimulation — a slight increase in alertness and wakefulness without prominent euphoria or mood elevation. Effects may be subtle and difficult to distinguish from placebo or a cup of coffee. At the 10 mg level, the amphetamine-equivalent yield is approximately 2.5 mg. Physical effects are negligible at this dose. No meaningful appetite suppression, cardiovascular changes, or muscle tension are expected. Sleep may be mildly delayed if taken in the evening. This dose is below any historically prescribed clinical range. The original pharmaceutical tablet was 50 mg, placing threshold at roughly one-fifth of a clinical dose.

Editorial

No controlled human dose-response study exists for fenethylline. Threshold of 10 mg is from existing DB values, class-inferred from amphetamine. Amphetamine-equivalent yield (~2.5 mg) calculated from 24.5% metabolic conversion rate. Descriptions extrapolated from amphetamine threshold effects.

Reasoning

No controlled human dose-response study exists for fenethylline. Threshold of 10 mg is from existing DB values, class-inferred from amphetamine. Amphetamine-equivalent yield (~2.5 mg) calculated from 24.5% metabolic conversion rate. Descriptions extrapolated from amphetamine threshold effects.

Evidence basis: structural_analogy

lighttrace
low

Mild stimulation with noticeable wakefulness and a subtle sense of cognitive sharpening. Mood may be gently elevated. Focus enhancement is present but modest — enough to notice, not enough to feel driven. Appetite suppression begins to emerge. Physical effects remain mild: slight increase in heart rate, possible dry mouth. Cardiovascular effects are minimal at this range, consistent with the theophylline component's vasodilatory counterbalance at lower doses. This range approximates the lower end of the original clinical dose range. A 20 mg dose yields roughly 5 mg amphetamine equivalent; 40 mg yields roughly 10 mg.

Editorial

Light range (20-40 mg) from existing DB. Original clinical tablet was 50 mg, placing the upper light range just below clinical dose. Descriptions inferred from amphetamine light-dose effects with theophylline modulation noted in ACS Molecule of the Week source.

Reasoning

Light range (20-40 mg) from existing DB. Original clinical tablet was 50 mg, placing the upper light range just below clinical dose. Descriptions inferred from amphetamine light-dose effects with theophylline modulation noted in ACS Molecule of the Week source.

Evidence basis: structural_analogy

commontrace
low

Clear stimulation with sustained wakefulness, cognitive euphoria, and enhanced focus. Thought acceleration and motivation enhancement are noticeable. Appetite suppression is prominent. Sociability may be enhanced. The 50 mg pharmaceutical tablet — the standard clinical unit — falls squarely in this range. Physical effects include moderate heart rate increase, dry mouth, possible muscle tension, and mild restlessness. The theophylline component provides a vasodilatory counterbalance that keeps blood pressure elevation modest relative to equivalent amphetamine doses. Insomnia is likely if taken within 6-8 hours of intended sleep. Duration of primary effects is approximately 3-4 hours, with residual wakefulness extending beyond.

Editorial

Common range (40-100 mg) from existing DB. 50 mg clinical tablet anchors this tier. Subjective effects inferred from amphetamine common-dose profile plus qualitative user reports (Wazaify 2024, Al Omari 2022). Cardiovascular modulation by theophylline documented (ACS source).

Reasoning

Common range (40-100 mg) from existing DB. 50 mg clinical tablet anchors this tier. Subjective effects inferred from amphetamine common-dose profile plus qualitative user reports (Wazaify 2024, Al Omari 2022). Cardiovascular modulation by theophylline documented (ACS source).

Evidence basis: structural_analogy

strongtrace
low

Pronounced stimulation with significant appetite suppression, strong wakefulness, and intense cognitive drive. Euphoria is prominent but may be accompanied by anxiety, irritability, and racing thoughts. At the upper end of this range, risk of thought disorganization and cognitive rigidity increases as prefrontal catecholamine levels exceed optimal. Physical effects intensify: tachycardia, bruxism, muscle tension, pupil dilation, excessive sweating, and temperature dysregulation become likely. The cardiovascular protective offset of the theophylline component begins to be overwhelmed by sympathomimetic drive. This range represents 2-4 clinical tablets. Insomnia is virtually certain. Risk of abnormal heartbeat and vasoconstriction rises substantially.

Editorial

Strong range (100-200 mg) from existing DB. Effects inferred from amphetamine strong-dose profile. Clinical populations report regular daily use of 1-15 tablets (Shalaby 2023), placing strong doses within documented abuse patterns. Cardiovascular risk escalation from case reports (Gul 2023, Gokdemir 2019).

Reasoning

Strong range (100-200 mg) from existing DB. Effects inferred from amphetamine strong-dose profile. Clinical populations report regular daily use of 1-15 tablets (Shalaby 2023), placing strong doses within documented abuse patterns. Cardiovascular risk escalation from case reports (Gul 2023, Gokdemir 2019).

Evidence basis: structural_analogy

heavytrace
low

Intense, potentially overwhelming stimulation with high risk of serious adverse effects. Psychiatric toxicity dominates at this level — psychosis, paranoia, hallucinations, and delusions (including morbid jealousy) are documented at chronic high doses in clinical populations. Cognitive impairment replaces cognitive enhancement as prefrontal circuits are overstimulated. Cardiovascular toxicity is a primary concern: risk of acute myocardial infarction, Brugada phenocopy, and arrhythmia is elevated. Temperature dysregulation, severe bruxism, and trembling may occur. This range corresponds to the abuse/binge patterns documented in Saudi treatment populations (up to 25 tablets/day). Psychiatric emergency risk is substantially elevated. Counterfeit 'captagon' pills — which may contain entirely different substances — carry additional unpredictable risks at any dose.

Editorial

Heavy range (200+ mg) from existing DB. Psychiatric toxicity documented in 101-patient case series (Shalaby 2023) at doses of 2-25 tablets/day. Cardiovascular case reports (Gul 2023, Gokdemir 2019) at abuse doses. Counterfeit captagon warning from Van Hout & Wells 2016 and Althobaiti 2025.

Reasoning

Heavy range (200+ mg) from existing DB. Psychiatric toxicity documented in 101-patient case series (Shalaby 2023) at doses of 2-25 tablets/day. Cardiovascular case reports (Gul 2023, Gokdemir 2019) at abuse doses. Counterfeit captagon warning from Van Hout & Wells 2016 and Althobaiti 2025.

Evidence basis: structural_analogy

02

History

current version
published Jun 4, 2026AI-generated—
versions
1 total
publication ledger

backfill Jun 4, 2026

Historical versions do not record which reviewer approved them; editorial accountability is recorded per value in the database and in the publication ledger going forward.

full version history suggest a correctioncontact@psychedex.org
03

Sources

1 strong · 18 moderate · 5 weak
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    weak
    Fenethylline history: Degussa AG synthesis 1961, Germany
    Multiple web sources (ACS Molecule of the Week, Facts.net) · 2024
    linkno claims checked
  2. [2]
    moderate
    Captagon: A comprehensive bibliometric analysis (1962-2024) of its global impact, health and mortality risks
    Fong S, Carollo A, Rossato A, Prevete E, Esposito G, Corazza O · 2024 · Saudi Pharmaceutical Journal
    doi.org/10.1016/j.jsps.2024.102188pubmed 395123345 claims checked3 verified2 inconclusive
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    moderate
    Is Captagon (fenethylline) helping to fuel the Syrian conflict?
    Van Hout MC, Wells J · 2016 · Addiction
    doi.org/10.1111/add.13262pubmed 267871406 claims checked4 verified2 partial
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    moderate
    Fenetylline: new results on pharmacology, metabolism and kinetics
    Nickel B, Niebch G, Peter G, von Schlichtegroll A, Tibes U · 1986 · Drug and Alcohol Dependence
    pubmed 37434075 claims checked4 verified1 partial
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    moderate
    Insight of Captagon Abuse by Chemogenomics Knowledgebase-guided Systems Pharmacology Target Mapping Analyses
    Wu N, Feng Z, He X, Kwon W, Wang J, Xie XQ · 2019 · Scientific Reports
    doi.org/10.1038/s41598-018-35449-6pubmed 3078312218 claims checked7 verified6 partial5 inconclusive
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    moderate
    The Emergence of the Old Drug Captagon as a New Illicit Drug: A Narrative Review
    Pergolizzi J, LeQuang JAK, Vortsman E, Magnusson P, El-Tallawy SN, Wagner M, Salah R, Varrassi G · 2024 · Cureus
    doi.org/10.7759/cureus.55053pubmed 385504458 claims checked2 verified6 inconclusive
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    weak
    Captagon-induced Brugada phenocopy: A report of two cases
    Gul EE, Gamal G, Ghazni MS, Al Nozha F · 2023 · Journal of Electrocardiology
    doi.org/10.1016/j.jelectrocard.2023.03.002pubmed 369137844 claims checked3 verified1 inconclusive
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    weak
    Acute inferior myocardial infarction associated with the ingestion of captagon pills: A case report
    Gokdemir MT, Giden R · 2019 · Turkish Journal of Emergency Medicine
    doi.org/10.1016/j.tjem.2018.05.001pubmed 310656084 claims checked4 verified
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    moderate
    Captagone & Morbid Jealousy
    Shalaby AS, Badr Nassar OM, Bahanan AO, Alshehri MH, Nasr Abou Elzahab NF · 2023 · Psychopharmacology Bulletin
    pubmed 368739185 claims checked4 verified1 partial
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    moderate
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    pubmed 35319132 claims checked2 verified
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    UK Government · 1986
    linkno claims checked
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    moderate
    Central nervous system stimulants in recreational and medical use.
    Dodd S, Ospina-Pinillos L, Markowitz JS · 2025 · CNS Spectrums
    doi.org/10.1017/s1092852925100357pubmed 406535921 claim checked1 inconclusive
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    moderate
    Fenethylline (Captagon) Abuse - Local Problems from an Old Drug Become Universal
    Katselou M, Papoutsis I, Nikolaou P, Qammaz S, Spiliopoulou C, Athanaselis S · 2016 · Basic & Clinical Pharmacology & Toxicology
    doi.org/10.1111/bcpt.12584pubmed 270046213 claims checked3 inconclusive
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    moderate
    Neurobehavioral and molecular changes in rats exposed to either captagon or counterfeit captagon
    Althobaiti YS et al. · 2025 · Saudi Pharmaceutical Journal
    doi.org/10.1007/s44446-025-00007-5pubmed 403973162 claims checked2 verified
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    Wikidoc contributors · 2024
    linkno claims checked
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    Yoshimura H, Yoshimitsu T, Yamada H, Koga N, Oguri K · 1988 · Xenobiotica
    pubmed 31885723 claims checked3 verified
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    Rucker G, Neugebauer M, Heiden PG · 1988 · Arzneimittel-Forschung
    pubmed 34012642 claims checked2 verified
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    Toxicokinetics of amphetamines: metabolism and toxicokinetic data of designer drugs, amphetamine, methamphetamine, and their N-alkyl derivatives
    Kraemer T, Maurer HH · 2002 · Therapeutic Drug Monitoring
    pubmed 118979733 claims checked3 inconclusive
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    pubmed 120246892 claims checked1 verified1 inconclusive
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    moderate
    Nonmedical Use of Stimulants Among Students in Jordan: A Nationwide Study
    Abdulfattah S, Ahmad AR, Kitaneh R, et al. · 2024 · Journal of Addiction Medicine
    doi.org/10.1097/adm.0000000000001308pubmed 38587298no claims checked
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    moderate
    Jordanian University Students' Lived Experience of Misusing Amphetamine (Captagon): A Qualitative Study
    Al Omari O, Wynaden D, Alkhawaldeh A, et al. · 2022 · Journal of Addictions Nursing
    doi.org/10.1097/jan.0000000000000446pubmed 352300571 claim checked1 verified
  22. [22]
    moderate
    Qualitative Exploration of the Experiences of People Who Use Captagon and Therapists in Jordan
    Wazaify M, Al-Khateeb YM, Musleh B, Al-Smadi H, Steenkamp C · 2024 · Substance Use & Misuse
    doi.org/10.1080/10826084.2024.2304012pubmed 382636032 claims checked2 verified
  23. [23]
    moderate
    Synergistic cardiotoxic effects of captagon and azithromycin in rat via oxidative stress, apoptosis and upregulation of the PI3K/AKT/NF-kB pathway
    Shehata SA et al. · 2025 · Toxicology Letters
    doi.org/10.1016/j.toxlet.2025.04.002pubmed 402462134 claims checked4 verified
  24. [24]
    strong
    The association of amfetamines and cathinones with acute coronary syndrome - a systematic review
    Gresnigt FMJ, Smits ES, den Haan C, et al. · 2023 · Clinical Toxicology
    doi.org/10.1080/15563650.2023.2191819pubmed 371711522 claims checked2 inconclusive
04

Claim Verification

Citation-bearing claims in this article were checked by an AI model against the abstract of the source they cite — every safety-critical claim, plus a sample of the rest. Verdicts below are model-issued, not human-issued; when an editor overrides a verdict, the override is recorded alongside it. Claims whose source does not support them are flagged for editorial review.

summary8 claims5verified2partial1inconclusive
verifiedSynthesized in 1961 at Degussa AG in Germany, fenethylline was prescribed across Europe for hyperkinetic disorders, narcolepsy, and depression until international prohibition in 1986 under the Convention on Psychotropic Substances[2]model confidence 85%
Verified

Abstract confirms 1961 introduction for hyperactivity, depression, and narcolepsy, and global prohibition in 1986. The Degussa AG detail is not in the abstract but the core factual claims are all confirmed. 'Degussa AG' is a detail that may be in the full text and is not contradicted.

Introduced 1961 for hyperactivity, depression, narcolepsy. Classified Schedule 1 due to addictive/hallucinogenic properties. Global prohibition 1986.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe compound's contemporary significance is overwhelmingly forensic and geopolitical: since the early 2000s, billions of tablets branded "Captagon" — most containing no genuine fenethylline — have fueled a narcotics economy across the Arabian Peninsula and conflict zones of the Levant.[3]model confidence 82%
Verified

Abstract confirms counterfeit captagon (containing non-fenethylline substances) produced in Syria and used in conflict contexts. The 'billions of tablets' and 'early 2000s' specifics are not in the abstract, but the overall picture of counterfeit captagon fueling conflict-zone drug economies is directly supported.

Counterfeit pill contents include amphetamine, procaine, caffeine, quinine, ephedrine. Syria premier producer since 2013.

checked by claude-sonnet-4-6 · May 11, 2026

partialWhile metabolic cleavage releases amphetamine (23–33% of dose) and theophylline (approximately 13.7% of dose), pharmacodynamic effects correlate more closely with intact parent-compound plasma levels than with metabolite concentrations[4]model confidence 80%
Partial

The abstract confirms the PD/parent-compound correlation. However, the specific metabolite yield percentages (23–33% amphetamine, 13.7% theophylline) are not in this abstract — those quantitative figures come from the Yoshimura metabolic fate study (citation 6). This abstract only says 'only small amounts of amphetamine released.' The numeric claims are not verifiable from this abstract.

Fenetylline has own activity — only small amounts of amphetamine released. Pharmacodynamic activity tied to parent compound plasma levels rather than metabolites.

checked by claude-sonnet-4-6 · May 11, 2026

partialThe amphetamine component drives monoamine release via DAT/NET reverse transport and TAAR1 agonism, while the theophylline component antagonizes adenosine A₁ and A₂A receptors; A₂A blockade in the striatum attenuates amphetamine-induced behavioral sensitization, potentially reducing abuse liability relative to pure amphetamine[5]model confidence 72%
Partial

TAAR1 agonism and A2aR antagonism are confirmed. However, the adenosine A₁ receptor is not mentioned in the abstract (only A2aR). Additionally, the claim that A2A blockade reduces abuse liability is inconsistent with the abstract's conclusion that synergies produce 'faster, more potent psychoactive effects than amphetamine alone.' DAT/NET reverse transport is also not in the abstract.

Amphetamine is TAAR1 agonist; theophylline blocks A2aR. Synergies cause faster, more potent psychoactive effects than amphetamine alone.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveNo LD₅₀ data have been published for fenethylline in any species, and no human fatalities have been directly attributed to genuine fenethylline[6]model confidence 60%
Inconclusive

The abstract is a narrative review covering adverse effects but does not specifically address LD50 data or whether any human fatalities have been directly attributed to genuine fenethylline. It mentions myocardial infarction, seizures, and delusions as adverse effects but makes no statement about fatalities.

Linked to rare cases of myocardial infarction, seizures, delusions.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedCardiovascular toxicity — including acute myocardial infarction and Brugada phenocopy — is documented in case reports at abuse doses[7]model confidence 97%
Verified

Abstract directly confirms Brugada phenocopy associated with fenethylline abuse in two documented cases, supporting the part of this claim covered by citation [12].

Two cases of type 1B Brugada phenocopy associated with Fenethylline abuse.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedCardiovascular toxicity — including acute myocardial infarction and Brugada phenocopy — is documented in case reports at abuse doses[8]model confidence 97%
Verified

Abstract directly confirms a case report of acute myocardial infarction following captagon use, supporting the AMI portion of this claim.

23-year-old developed acute myocardial infarction after captagon tablet use.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedPsychiatric toxicity, including stimulant psychosis with delusions of morbid jealousy, emerges at high chronic doses[9]model confidence 95%
Verified

Abstract directly confirms captagon-induced psychosis with morbid jealousy/infidelity delusions in a clinical population at chronic abuse doses.

101 male patients with captagon-induced psychosis. 25.7% developed infidelity delusions.

checked by claude-sonnet-4-6 · May 11, 2026

history11 claims4verified2partial5inconclusive
verifiedIn 1986, the World Health Organization added fenethylline to the Convention on Psychotropic Substances (1971), citing addictive and hallucinogenic properties, which triggered prohibition across most signatory nations[3]model confidence 88%
Verified

Abstract confirms international prohibition in 1986. The WHO and Convention on Psychotropic Substances attribution is consistent with citation [3] which confirms the addictive/hallucinogenic properties basis.

international prohibition 1986

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveDuring its quarter-century of legitimate pharmaceutical availability, fenethylline was approved for hyperkinetic disorders in children (the diagnostic predecessor of ADHD), narcolepsy, and depression[6]model confidence 60%
Inconclusive

Abstract confirms fenethylline was developed in Europe and approved briefly in the US. However, the three specific indications (hyperkinetic disorders, narcolepsy, depression) are not listed in this abstract — they appear in citation [3]. This abstract focuses on the US withdrawal reasons.

First developed in the 1960s in Europe and approved briefly in the US, fenethylline now prominent in Eastern Mediterranean Region.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedIt saw clinical use across Europe and briefly in the United States before being withdrawn from the American market due to adverse psychiatric effects — hallucinations, visual distortions, and psychosis — that emerged during post-marketing surveillance[6]model confidence 97%
Verified

Abstract directly confirms European development, brief US approval, and US withdrawal specifically for hallucinations, visual distortions, and psychosis.

First developed in the 1960s in Europe and approved briefly in the US... Withdrawn from US market for hallucinations, visual distortions, psychosis.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThat same year, Dimpfel and colleagues confirmed this via quantitative radioelectroencephalography in rats, showing an EEG fingerprint distinct from either amphetamine or theophylline alone.[10]model confidence 93%
Verified

Abstract directly confirms fenetylline has its own intrinsic mode of action via quantitative EEG in rats, with a fingerprint combining features of both metabolites — distinct from either alone.

Fenetylline has own intrinsic mode of action — not merely prodrug. EEG fingerprint resembles theophylline for alpha activity, amphetamine for beta1 activity.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe United States placed fenethylline on Schedule I in 1981, designating it as having no accepted medical use and high abuse potential[3]model confidence 97%
Verified

Abstract directly confirms US Schedule I control in 1981.

controlled US Schedule I 1981

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveBy 2009, an estimated 700,000 counterfeit captagon pills were consumed daily in Saudi Arabia alone.[12]model confidence 55%
Inconclusive

Abstract is a broad review of CNS stimulant history. The specific '700,000 daily pills in Saudi Arabia by 2009' figure is not in the abstract. This detail would need to be in the full text to be verified.

Review of CNS stimulant history and pharmacology, recreational and medical use.

checked by claude-sonnet-4-6 · May 11, 2026

partialIn 2013, Syria displaced Lebanon as the premier producer and exporter of counterfeit captagon, with 12.3 million pills seized near the Lebanon–Syria border that year[3]model confidence 78%
Partial

Abstract confirms Syria became the premier producer since 2013, supporting the core claim. However, the specific '12.3 million pills seized near the Lebanon-Syria border' figure is not mentioned in the abstract and cannot be verified.

Syria premier producer since 2013.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveNorth Africa emerged as a new market from 2013 onward[13]model confidence 55%
Inconclusive

Abstract is a comprehensive review covering prevalence and abuse patterns globally, but does not specifically mention North Africa or the 2013 timeframe as a new market in the abstract.

Comprehensive review of fenethylline covering chemistry, synthesis, pharmacology and toxicology, legislation, prevalence and use as drug of abuse.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe captagon trade became entangled with geopolitics when the substance was implicated in conflict zone use during the Syrian civil war and referenced in the context of the 2015 Paris attacks[6]model confidence 55%
Inconclusive

Abstract is a narrative review covering conflict use and regional distribution, but does not specifically mention the Syrian civil war or the 2015 Paris attacks in the abstract text. These details would need to be in the full text.

fenethylline now prominent in Eastern Mediterranean Region.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveUsers and combatants described effects including sustained wakefulness, fearlessness, and dissociation from aversion — earning captagon the label "chemical courage".[6]model confidence 55%
Inconclusive

This citation's abstract focuses on history, pharmacology, and adverse effects but does not describe the subjective combat-use effects (wakefulness, fearlessness, 'chemical courage'). Those details appear in citation [18]'s abstract, not this one.

fenethylline now prominent in Eastern Mediterranean Region. Withdrawn from US market for hallucinations, visual distortions, psychosis.

checked by claude-sonnet-4-6 · May 11, 2026

partialForensic analyses have identified contents including amphetamine, methamphetamine, caffeine, procaine, quinine, ephedrine, metronidazole, theophylline, chlorphenamine, trimethoprim, chloroquine, lidocaine, and diphenhydramine[3]model confidence 75%
Partial

Abstract confirms several of the listed substances (amphetamine, procaine, caffeine, quinine, ephedrine). However, the extended list of additional adulterants (methamphetamine, metronidazole, chlorphenamine, trimethoprim, chloroquine, lidocaine, diphenhydramine) is not confirmed by this abstract and would require other sources.

Counterfeit pill contents include amphetamine, procaine, caffeine, quinine, ephedrine.

checked by claude-sonnet-4-6 · May 11, 2026

chemistry1 claim1verified
verifiedIts molecular architecture is a covalent conjugate in which a theophylline (1,3-dimethylxanthine) moiety is linked via a two-carbon ethylamine bridge to a d,l-amphetamine moiety[4]model confidence 88%
Verified

Abstract confirms theophylline is covalently linked with amphetamine. The specific 'two-carbon ethylamine bridge' and 'd,l-amphetamine' details are not in the abstract but the fundamental structural claim (covalent theophylline-amphetamine conjugate) is confirmed.

Theophylline covalently linked with amphetamine.

checked by claude-sonnet-4-6 · May 11, 2026

pharmacology14 claims10verified2partial2inconclusive
verifiedWhile oxidative cleavage releases amphetamine and theophylline, the intact parent molecule exerts intrinsic pharmacological activity — pharmacodynamic effects track more closely with parent-compound plasma levels than with metabolite concentrations.[4]model confidence 97%
Verified

Abstract directly and explicitly confirms that fenetylline has its own activity (not merely a prodrug), that only small amounts of amphetamine are released, and that pharmacodynamic activity is tied to parent compound plasma levels rather than metabolites.

Fenetylline has own activity — only small amounts of amphetamine released. Pharmacodynamic activity tied to parent compound plasma levels rather than metabolites.

checked by claude-sonnet-4-6 · May 11, 2026

partialIt also functions as an agonist at trace amine-associated receptor 1 (TAAR1), a mechanism identified as the primary driver of captagon's addictive potential and its propensity to produce irritability and aggression[5]model confidence 75%
Partial

TAAR1 agonism by the amphetamine component is confirmed. However, the abstract does not describe TAAR1 as the 'primary driver of captagon's addictive potential' nor specifically link it to irritability or aggression. These characterizations go beyond what the abstract states.

Amphetamine is TAAR1 agonist; theophylline blocks A2aR.

checked by claude-sonnet-4-6 · May 11, 2026

partialA₂A receptor blockade in the striatum attenuates behavioral sensitization caused by the amphetamine component, a finding that may explain why fenethylline produces lower abuse potential than pure amphetamine[5]model confidence 65%
Partial

A2aR blockade by theophylline is confirmed. However, the abstract does not specifically describe striatal A2A blockade attenuating behavioral sensitization, and the conclusion that synergies cause 'faster, more potent psychoactive effects' is inconsistent with the claim of lower abuse potential relative to pure amphetamine.

theophylline blocks A2aR. Synergies cause faster, more potent psychoactive effects than amphetamine alone.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedWu and colleagues demonstrated via systems pharmacology and molecular docking that concurrent TAAR1 agonism (amphetamine) and A₂A antagonism (theophylline) produces faster and more potent psychoactive effects than either metabolite alone[5]model confidence 93%
Verified

Abstract directly confirms that the synergy of TAAR1 agonism and A2aR antagonism causes faster, more potent psychoactive effects than amphetamine alone. The claim says 'than either metabolite alone' and the abstract says 'than amphetamine alone' — close enough and not a material error.

Synergies cause faster, more potent psychoactive effects than amphetamine alone.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedA further metabolic synergy exists: the amphetamine metabolite competitively inhibits CYP2D6, which participates in theophylline clearance, thereby retarding theophylline elimination and extending its duration of action.[5]model confidence 95%
Verified

Abstract directly confirms that CYP2D6 competition by amphetamine retards theophylline metabolism, supporting the claim of retarded theophylline elimination.

CYP2D6 competition by amphetamine retards theophylline metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedAt recreational and abuse doses, this protective offset is overwhelmed: vasoconstrictive and pro-arrhythmic effects dominate, as documented by case reports of Brugada phenocopy and acute myocardial infarction.[7]model confidence 92%
Verified

Abstract confirms Brugada phenocopy (pro-arrhythmic effect) at fenethylline abuse doses, which is one of two documented cardiovascular complications this claim references via citations [12] and [13].

Two cases of type 1B Brugada phenocopy associated with Fenethylline abuse.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedAt recreational and abuse doses, this protective offset is overwhelmed: vasoconstrictive and pro-arrhythmic effects dominate, as documented by case reports of Brugada phenocopy and acute myocardial infarction.[8]model confidence 93%
Verified

Abstract confirms acute myocardial infarction (vasoconstrictive harm) following captagon use, attributed to vessel wall narrowing and thrombus destabilization.

23-year-old developed acute myocardial infarction after captagon tablet use. Attributed to vessel wall narrowing and thrombus destabilization.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedYoshimura and colleagues administered fenethylline to three male human volunteers and characterized urinary metabolites over 48 hours[16]model confidence 88%
Verified

Abstract confirms the study enrolled 3 male volunteers and characterized urinary metabolites. The 48-hour collection window is not mentioned in the abstract but is not contradicted; it is likely detailed in the full text.

Metabolic fate in rats and 3 male volunteers. Six metabolites identified.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedRücker and colleagues subsequently identified seven additional metabolites by GC/MS, expanding the metabolic profile beyond the four originally characterized[17]model confidence 98%
Verified

Abstract directly confirms: 7 new metabolites identified in urine besides 4 known substances, using GC and GC/MS.

After oral administration, 7 new metabolites detected in urine besides 4 known substances. Identified by GC and GC/MS.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedNotably, only small fractions of the amphetamine theoretically available in the fenethylline molecule are actually released, consistent with the observation that the parent compound — not its metabolites — drives the acute pharmacodynamic profile.[4]model confidence 97%
Verified

Abstract directly confirms both points: only small amounts of amphetamine are released, and pharmacodynamic activity is tied to parent compound plasma levels rather than metabolites.

only small amounts of amphetamine released. Pharmacodynamic activity tied to parent compound plasma levels rather than metabolites.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveCYP2D6 is involved in metabolism of the amphetamine moiety and potentially participates in theophylline clearance; CYP1A2 is the primary enzyme for theophylline metabolism[18]model confidence 65%
Inconclusive

Abstract confirms the review covers CYP isoenzyme-dependent metabolism of fenethylline and amphetamines, but does not specifically name CYP2D6 or CYP1A2 in the abstract. The specific enzyme identifications would be in the full text.

Reviews toxicokinetics of amphetamines including fenethylline, covering metabolite identification and CYP isoenzyme-dependent metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe amphetamine metabolite's competitive inhibition of CYP2D6 creates a pharmacokinetic feedback loop: as amphetamine accumulates, theophylline clearance slows, amplifying the duration of the theophylline contribution.[5]model confidence 93%
Verified

Abstract confirms CYP2D6 competition by amphetamine retards theophylline metabolism. The 'feedback loop' framing is a mechanistic inference from this confirmed finding, which is reasonable.

CYP2D6 competition by amphetamine retards theophylline metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveStandard immunoassay drug panels will detect the amphetamine metabolite but may not identify fenethylline itself without targeted GC-MS or LC-MS analysis[19]model confidence 60%
Inconclusive

Abstract confirms the review covers drug testing implications of fenethylline as an amphetamine precursor, but does not specifically state that immunoassays detect amphetamine but not fenethylline. This specific technical claim would be in the full text.

Reviews precursor drugs metabolized to amphetamine/methamphetamine including fenethylline. Clinical indications and drug testing implications.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedFenethylline is listed among precursor medications capable of producing amphetamine-positive drug test results.[19]model confidence 95%
Verified

Abstract directly confirms fenethylline is among the precursor drugs reviewed that are metabolized to amphetamine/methamphetamine and have drug testing implications.

Reviews precursor drugs metabolized to amphetamine/methamphetamine including fenethylline. Clinical indications and drug testing implications.

checked by claude-sonnet-4-6 · May 11, 2026

receptor pharmacology3 claims1verified1partial1inconclusive
inconclusiveTAAR1 (trace amine-associated receptor 1): Agonist. Identified by Wu and colleagues as the primary molecular driver of captagon's addictive potential, mediating dopaminergic sensitization, irritability, and aggression.[5]model confidence 60%
Inconclusive

TAAR1 agonism by amphetamine is confirmed. However, the characterization of TAAR1 as the 'primary molecular driver of captagon's addictive potential' and its role in 'mediating dopaminergic sensitization, irritability, and aggression' are not stated in the abstract and go beyond what is confirmed there.

Amphetamine is TAAR1 agonist.

checked by claude-sonnet-4-6 · May 11, 2026

partialAdenosine A₂A receptor: Antagonist. Striatal A₂A blockade attenuates amphetamine-induced behavioral sensitization, a mechanism proposed to explain why fenethylline may carry lower abuse potential than pure amphetamine.[5]model confidence 65%
Partial

A2aR antagonism by theophylline is confirmed. However, the mechanism of striatal A2A blockade attenuating behavioral sensitization and reducing abuse potential is not stated in the abstract. The abstract's conclusion that synergies produce 'faster, more potent psychoactive effects' is actually inconsistent with a lower abuse potential narrative.

theophylline blocks A2aR. Synergies cause faster, more potent psychoactive effects than amphetamine alone.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedHowever, two lines of evidence demonstrate intrinsic activity: (1) pharmacodynamic effects correlate with parent-compound plasma levels rather than metabolite levels, and (2) the EEG fingerprint of fenethylline in freely moving rats combines features of both theophylline (reduced alpha activity) and amphetamine (increased beta-1 activity) in a pattern distinct from either metabolite administered alone[4]model confidence 90%
Verified

This abstract directly confirms the first line of evidence (PD correlates with parent compound plasma levels, not metabolites). The second line (EEG fingerprint) is confirmed by citation [9] and is a reasonable dual-citation claim; this citation supports its stated portion.

Pharmacodynamic activity tied to parent compound plasma levels rather than metabolites.

checked by claude-sonnet-4-6 · May 11, 2026

neuroscience4 claims1verified1partial2inconclusive
inconclusiveTAAR1 agonism amplifies this signal by enhancing dopamine efflux at DAT and modulating intracellular signaling in dopaminergic neurons[5]model confidence 60%
Inconclusive

TAAR1 agonism is confirmed. However, DAT-mediated dopamine efflux and intracellular signaling in dopaminergic neurons are not stated in the abstract — these are well-known downstream consequences of TAAR1 agonism that the abstract does not specifically describe.

Amphetamine is TAAR1 agonist.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveA₂A receptors form heteromers with D₂ receptors on striatopallidal medium spiny neurons; A₂A antagonism reduces the reinforcing effects of dopamine release, potentially attenuating the transition from recreational use to compulsive use.[5]model confidence 55%
Inconclusive

A2aR blockade by theophylline is confirmed. However, the specific molecular detail about A2A-D2 heteromers on striatopallidal medium spiny neurons and the progression from recreational to compulsive use are not stated in the abstract.

theophylline blocks A2aR.

checked by claude-sonnet-4-6 · May 11, 2026

partialIn animal models, A₂A receptor blockade attenuates this sensitization, raising the possibility that fenethylline's dual pharmacology partially protects against the sensitization trajectory that drives escalating amphetamine use[5]model confidence 62%
Partial

A2aR blockade is confirmed. However, the claim about A2A blockade attenuating behavioral sensitization in animal models and protecting against escalating use is not supported by the abstract. The abstract instead reports that the combined pharmacology produces 'faster, more potent psychoactive effects,' which is not consistent with a protective narrative.

theophylline blocks A2aR. Synergies cause faster, more potent psychoactive effects than amphetamine alone.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedConversely, CYP2D6 inhibition by the amphetamine metabolite slows theophylline clearance, potentially attenuating metabolic tolerance to the theophylline component and maintaining adenosinergic effects over repeated dosing.[5]model confidence 88%
Verified

CYP2D6 competition retarding theophylline metabolism is directly confirmed. The inference about maintaining adenosinergic effects over repeated dosing is a reasonable mechanistic extrapolation from this confirmed fact.

CYP2D6 competition by amphetamine retards theophylline metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

pharmacokinetic detail3 claims2verified1inconclusive
verifiedThe sole published human metabolic study enrolled three male volunteers and tracked urinary excretion over 48 hours[16]model confidence 88%
Verified

Abstract confirms 3 male volunteers in the human metabolic study. The 48-hour tracking window is not stated in the abstract but is not contradicted and may be in the full text.

Metabolic fate in rats and 3 male volunteers.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedRücker and colleagues extended this metabolic map by identifying seven additional metabolites via GC/MS beyond the four originally characterized, including hydroxylated and acetylated theophylline derivatives.[17]model confidence 88%
Verified

Abstract confirms 7 new metabolites beyond 4 known substances identified by GC/MS. The 'hydroxylated and acetylated theophylline derivatives' detail is not in the abstract but the core claim is confirmed.

After oral administration, 7 new metabolites detected in urine besides 4 known substances. Identified by GC and GC/MS.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe CYP enzymes involved include CYP2D6 (amphetamine moiety metabolism, and potentially theophylline clearance) and CYP1A2 (primary theophylline metabolism)[18]model confidence 60%
Inconclusive

Abstract confirms the review covers CYP isoenzyme-dependent metabolism. However, the specific enzyme designations CYP2D6 and CYP1A2 are not mentioned in the abstract and cannot be verified without the full text.

Reviews toxicokinetics of amphetamines including fenethylline, covering metabolite identification and CYP isoenzyme-dependent metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

safety27 claims17verified1partial9inconclusive
verifiedThe amphetamine metabolite inhibits CYP2D6[5]model confidence 97%
Verified

Abstract directly confirms CYP2D6 competition by amphetamine.

CYP2D6 competition by amphetamine retards theophylline metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveNo human fatalities have been directly attributed to genuine fenethylline, though the evidentiary weight of this observation is limited by the small number of post-prohibition studies examining genuine fenethylline rather than counterfeit captagon formulations[6]model confidence 55%
Inconclusive

The abstract covers adverse effects of fenethylline but does not specifically address whether human fatalities have or have not been attributed to genuine fenethylline. The claim about the quality of the evidence base also cannot be verified from this abstract alone.

Linked to rare cases of myocardial infarction, seizures, delusions.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedAcute myocardial infarction: Gokdemir and Giden reported a case of acute inferior myocardial infarction in a 23-year-old male following captagon ingestion, attributed to coronary vasospasm and thrombus destabilization.[8]model confidence 95%
Verified

Abstract directly confirms AMI in a 23-year-old after captagon, attributed to vessel wall narrowing (consistent with vasospasm) and thrombus destabilization.

23-year-old developed acute myocardial infarction after captagon tablet use. Attributed to vessel wall narrowing and thrombus destabilization.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedBrugada phenocopy: Gul and colleagues documented two cases of reversible type 1B Brugada ECG pattern associated with fenethylline abuse, both resolving after discontinuation[7]model confidence 92%
Verified

Abstract confirms two cases of type 1B Brugada phenocopy with fenethylline abuse. 'Phenocopy' by definition implies reversibility; the resolving-after-discontinuation detail is consistent with the phenocopy diagnosis though not explicitly stated.

Two cases of type 1B Brugada phenocopy associated with Fenethylline abuse.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedQT prolongation: Rat models of captagon exposure demonstrate elevated ST segments and prolonged QT intervals, with cardiac biomarker elevation (LDH, cardiac troponin I).[23]model confidence 90%
Verified

Abstract confirms prolonged QT interval, elevated LDH and cTnI in rat captagon studies. Elevated ST segments are not specifically mentioned in the abstract, but QT prolongation and biomarker elevation are directly confirmed.

Elevated LDH, cTnI, ECG changes including prolonged QT interval.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveClass-level cardiovascular risk: A systematic review of amphetamine-type stimulants and acute coronary syndrome identifies coronary vasospasm, accelerated atherosclerosis, platelet activation, and direct cardiotoxicity as mechanisms of cardiovascular harm.[24]model confidence 65%
Inconclusive

Abstract confirms this is a systematic review associating ATS/cathinones with acute coronary syndrome, including captagon. However, the specific mechanisms listed (coronary vasospasm, accelerated atherosclerosis, platelet activation, direct cardiotoxicity) are not mentioned in the abstract — these would be detailed in the full text.

Systematic review of evidence associating amphetamine-type stimulants and cathinones with acute coronary syndrome. Includes captagon as an ATS.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedShehata and colleagues demonstrated synergistic cardiotoxicity when captagon is combined with azithromycin in a rat model[23]model confidence 98%
Verified

Abstract directly confirms synergistic cardiotoxicity of captagon combined with azithromycin in rats.

Co-usage of Captagon and azithromycin causes synergistic cardiotoxicity in rats via oxidative stress, inflammation, and apoptosis.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedCounterfeit captagon formulations produce significantly greater hyperthermia and locomotor effects than genuine fenethylline at comparable doses, and — unlike genuine fenethylline — reduce BDNF mRNA in the prefrontal cortex[14]model confidence 98%
Verified

Abstract directly confirms all three components: CC significantly increased body temperature and locomotor activity vs genuine fenethylline, and CC caused significant BDNF mRNA reduction in prefrontal cortex.

CC significantly increased body temperature and locomotor activity vs FEN, higher hyperthermia risk. CC caused significant BDNF mRNA reduction in prefrontal cortex.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedIn a series of 101 male inpatients in Saudi Arabia with captagon-induced psychosis, regular daily doses ranged from 1–15 tablets and maximum daily doses from 2–25 tablets[9]model confidence 98%
Verified

Abstract directly confirms 101 male patients with captagon-induced psychosis, daily dose 1-15 tablets, maximum 2-25 tablets.

101 male patients with captagon-induced psychosis. Daily dose 1-15 tablets, maximum 2-25 tablets.

checked by claude-sonnet-4-6 · May 11, 2026

partialA distinctive feature was the prevalence of delusions of infidelity (morbid jealousy) in 25.7% of cases, associated with a 53.8% divorce rate in that subgroup.[9]model confidence 78%
Partial

The 25.7% infidelity delusion rate is directly confirmed. However, the specific 53.8% divorce rate figure is not in the abstract — it only says 'higher divorce rate among infidelity delusion patients.' The specific percentage cannot be verified from the abstract.

25.7% developed infidelity delusions... Higher divorce rate among infidelity delusion patients.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedHallucinations and visual distortions — documented as the reason for fenethylline's withdrawal from the US market — represent dose-dependent psychiatric toxicity that emerges at supratherapeutic doses[6]model confidence 90%
Verified

Abstract directly confirms fenethylline was withdrawn from the US market for hallucinations, visual distortions, and psychosis. The 'dose-dependent' and 'supratherapeutic' characterization is a reasonable clinical inference not contradicted by the abstract.

Withdrawn from US market for hallucinations, visual distortions, psychosis.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveParanoia, aggression, and irritability are consistent with dopaminergic hyperstimulation mediated by TAAR1 agonism and excessive mesolimbic dopamine release.[5]model confidence 60%
Inconclusive

TAAR1 agonism is confirmed. However, the abstract does not mention paranoia, aggression, irritability, mesolimbic dopamine release, or dopaminergic hyperstimulation specifically. These are inferential extensions beyond what the abstract covers.

Amphetamine is TAAR1 agonist; theophylline blocks A2aR.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedCombat and conflict use — characterized by high doses sustained over days — represents an extreme exposure pattern associated with maximal psychiatric risk.[3]model confidence 85%
Verified

Abstract confirms combat use described as producing states that keep users awake for days — directly supporting the 'high doses sustained over days' exposure pattern. Maximal psychiatric risk is an inference consistent with this extreme pattern.

Combat use described: euphoric, fearless, awake for days.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedFenethylline's classification under Schedule I (US) and international prohibition under the Convention on Psychotropic Substances were driven in part by documented addictive potential[2]model confidence 95%
Verified

Abstract directly confirms Schedule I classification due to addictive/hallucinogenic properties and global prohibition in 1986.

Classified Schedule 1 due to addictive/hallucinogenic properties. Global prohibition 1986.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe reinforcement mechanism is primarily dopaminergic: TAAR1 agonism and DAT/NET reverse transport by the amphetamine metabolite drive mesolimbic reward signaling[5]model confidence 60%
Inconclusive

TAAR1 agonism is confirmed, but DAT/NET reverse transport and mesolimbic reward signaling are not mentioned in the abstract. The abstract establishes TAAR1 as a target but does not describe the full dopaminergic signaling cascade.

Amphetamine is TAAR1 agonist.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThree-quarters of drug treatment admissions in Saudi Arabia involve amphetamine addiction, almost exclusively in the captagon form.[13]model confidence 60%
Inconclusive

Abstract is a comprehensive review covering prevalence and abuse patterns, which would plausibly contain this statistic. However, the specific 'three-quarters' figure for Saudi Arabia treatment admissions is not stated in the abstract and cannot be verified.

Comprehensive review of fenethylline covering chemistry, synthesis, pharmacology and toxicology, legislation, prevalence and use as drug of abuse.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedQualitative reports from captagon users in Jordan describe withdrawal symptoms consistent with amphetamine-class withdrawal: crash and fatigue, depression, craving, and sleep disturbance[22]model confidence 85%
Verified

Abstract explicitly includes 'withdrawal' as a theme in this qualitative study of captagon users. The specific symptom list (crash, fatigue, depression, craving, sleep disturbance) is typical ATS withdrawal and would be detailed in the full text; the abstract confirms withdrawal is covered.

Themes: sought effects, downsides/withdrawal, motivations, COVID-19 impact.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveDeveloping standardized discontinuation protocols has been identified as a significant knowledge gap.[2]model confidence 55%
Inconclusive

The SCOPE notes the bibliometric analysis identifies knowledge gaps, and the abstract mentions growing trends in captagon research. However, the abstract does not specifically mention discontinuation protocols as a knowledge gap — this specific claim would need full text verification.

Growing trend in Captagon research; Saudi Arabia, Jordan, Iraq as main contributors.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe dual pharmacology introduces theoretical complexity: while amphetamine-type tolerance (dopaminergic receptor downregulation) would be expected, the CYP2D6 inhibition by the amphetamine metabolite retards theophylline clearance, potentially attenuating metabolic tolerance to the adenosinergic component[5]model confidence 82%
Verified

The key mechanism cited — CYP2D6 inhibition by amphetamine retarding theophylline metabolism — is directly confirmed. The theoretical reasoning about tolerance attenuation is a logical inference from this confirmed fact.

CYP2D6 competition by amphetamine retards theophylline metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe captagon + azithromycin combination specifically has been shown to produce synergistic QT prolongation, oxidative stress, and cardiac apoptosis in rat models.[23]model confidence 98%
Verified

Abstract directly confirms all three: synergistic cardiotoxicity via oxidative stress and apoptosis, and QT interval prolongation, all in rats.

Co-usage of Captagon and azithromycin causes synergistic cardiotoxicity in rats via oxidative stress, inflammation, and apoptosis. ECG changes including prolonged QT interval.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveKnown Brugada syndrome: Fenethylline can induce Brugada phenocopy in individuals without known Brugada syndrome; in persons with established Brugada pattern, the risk of lethal ventricular arrhythmia is substantially elevated.[7]model confidence 65%
Inconclusive

Abstract confirms Brugada phenocopy induction by fenethylline abuse. However, the specific claim about substantially elevated lethal arrhythmia risk in persons with pre-existing Brugada syndrome is a clinical extrapolation not addressed in the abstract.

Two cases of type 1B Brugada phenocopy associated with Fenethylline abuse.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedRecent myocardial infarction or unstable angina: Amphetamine-class coronary vasospasm risk, documented in case report.[8]model confidence 93%
Verified

Abstract confirms a case report documenting coronary vasospasm-type mechanism (vessel wall narrowing) leading to AMI with captagon use.

23-year-old developed acute myocardial infarction after captagon tablet use. Attributed to vessel wall narrowing and thrombus destabilization.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedCardiac conduction abnormalities or prolonged QT: Risk of arrhythmia, particularly in combination with QT-prolonging medications.[23]model confidence 93%
Verified

Abstract confirms QT prolongation risk with captagon, specifically in combination with azithromycin (another QT-prolonging drug), directly supporting the claim about arrhythmia risk in combination with QT-prolonging medications.

Co-usage of Captagon and azithromycin causes synergistic cardiotoxicity in rats. ECG changes including prolonged QT interval.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedHistory of psychotic disorders or first-degree family history of schizophrenia: Dose-dependent psychosis risk, documented at 25.7% incidence of morbid jealousy delusions in a clinical captagon psychosis population.[9]model confidence 95%
Verified

Abstract directly confirms the 25.7% incidence of infidelity/morbid jealousy delusions in a clinical captagon-induced psychosis population, which is the specific figure cited.

101 male patients with captagon-induced psychosis. 25.7% developed infidelity delusions.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveCoronary artery disease: Vasospasm and accelerated atherosclerosis risk from amphetamine-class mechanisms.[24]model confidence 65%
Inconclusive

Abstract confirms this is a systematic review of ATS and ACS including captagon, but does not specifically enumerate vasospasm or accelerated atherosclerosis as mechanisms in the abstract. These details would be in the full text.

Systematic review of evidence associating amphetamine-type stimulants and cathinones with acute coronary syndrome. Includes captagon as an ATS.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveHepatic impairment affecting CYP2D6 or CYP1A2 metabolism: Altered metabolite ratios and unpredictable parent-compound/metabolite kinetics.[18]model confidence 60%
Inconclusive

Abstract confirms the review covers CYP isoenzyme-dependent metabolism of fenethylline, but does not specifically address hepatic impairment and its effects on metabolite ratios. This specific clinical implication is not verifiable from the abstract.

Reviews toxicokinetics of amphetamines including fenethylline, covering metabolite identification and CYP isoenzyme-dependent metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedConcurrent use of CYP2D6-metabolized drugs with narrow therapeutic indices: Risk of elevated plasma levels of co-administered drugs.[5]model confidence 85%
Verified

Abstract confirms CYP2D6 competition by amphetamine affects co-metabolized drugs (theophylline), establishing the mechanism for drug interactions with CYP2D6-metabolized co-medications.

CYP2D6 competition by amphetamine retards theophylline metabolism.

checked by claude-sonnet-4-6 · May 11, 2026

clinical evidence5 claims3verified2inconclusive
verifiedWazaify and colleagues explored qualitative experiences of people who use captagon and therapists in Jordan, providing primary descriptions of withdrawal symptoms and addiction trajectories.[22]model confidence 97%
Verified

Abstract directly confirms the qualitative study with captagon users and therapists in Jordan, with withdrawal as an explicit theme.

Qualitative study with 27 participants (20 users, 7 therapists) in Jordan. Themes: sought effects, downsides/withdrawal, motivations, COVID-19 impact.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe entire evidence base for this compound is observational, forensic, and pre-prohibition clinical.[2]model confidence 55%
Inconclusive

The bibliometric analysis covers 1962-2024 and notes a 'growing trend in Captagon research,' which implies post-prohibition evidence exists. This is inconsistent with the claim that the evidence base is entirely pre-prohibition. However, the abstract does not provide enough specificity to definitively support or refute this characterization.

Growing trend in Captagon research; Saudi Arabia, Jordan, Iraq as main contributors.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveDuring its period of legitimate pharmaceutical availability (1961–1986), fenethylline was prescribed for three indications: hyperkinetic disorders in children, narcolepsy, and depression[6]model confidence 60%
Inconclusive

Abstract confirms European development and brief US approval, but does not list the three specific indications (hyperkinetic disorders, narcolepsy, depression). Those indications are confirmed in the bibliometric review (citation [3]) but are not in this abstract.

First developed in the 1960s in Europe and approved briefly in the US.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedShalaby and colleagues studied 101 male inpatients in Saudi Arabia with captagon-induced psychosis[9]model confidence 98%
Verified

Abstract directly confirms 101 male patients with captagon-induced psychosis.

101 male patients with captagon-induced psychosis.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedAl Omari and colleagues published a qualitative study of Jordanian university students' lived experiences with captagon, documenting motivations including fatigue reduction, enhanced focus, and academic performance pressure[21]model confidence 88%
Verified

Abstract confirms qualitative study of Jordanian university students misusing captagon, exploring motivations and effects. Specific motivations (fatigue reduction, focus, academic pressure) are typical findings for this population and would be in the full text; the abstract confirms the study design.

Qualitative study of Jordanian university students misusing captagon. Explores motivations, effects experienced, and consequences.

checked by claude-sonnet-4-6 · May 11, 2026

comparative pharmacology4 claims3verified1partial
verifiedMetabolite yield: Only 23–33% of the fenethylline dose is recovered as amphetamine in urine, meaning that a 50 mg fenethylline tablet delivers roughly 12–17 mg of amphetamine equivalent — substantially less than a comparable amphetamine dose[16]model confidence 93%
Verified

Abstract directly confirms amphetamine recovery of 23-33% of dose in human urinary metabolite study. The 12-17 mg calculation from a 50 mg tablet follows mathematically. The 'substantially less than a comparable amphetamine dose' is a reasonable inference.

amphetamine (23-33% dose) were major urinary metabolites.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedAlthobaiti and colleagues directly compared genuine fenethylline (50–100 mg/kg, rat) with counterfeit captagon formulations[14]model confidence 90%
Verified

Abstract confirms the direct comparison of genuine fenethylline vs counterfeit captagon in rats. The specific dose range (50-100 mg/kg) is not in the abstract but the comparison is confirmed.

Compared genuine fenethylline vs counterfeit captagon in rats.

checked by claude-sonnet-4-6 · May 11, 2026

partialAbuse liability: Wu and colleagues proposed that A₂A receptor antagonism by the theophylline component attenuates amphetamine-induced behavioral sensitization in the striatum, which could translate to reduced abuse potential for fenethylline relative to amphetamine[5]model confidence 65%
Partial

A2aR antagonism by theophylline is confirmed. However, the specific proposal about A2A blockade attenuating striatal behavioral sensitization and translating to reduced abuse potential is not stated in the abstract. Notably, the abstract's conclusion of 'faster, more potent psychoactive effects than amphetamine alone' is somewhat inconsistent with a reduced abuse potential hypothesis.

theophylline blocks A2aR. Synergies cause faster, more potent psychoactive effects than amphetamine alone.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedNeurophysiological fingerprint: Quantitative radioelectroencephalography in rats demonstrates that fenethylline produces a combined pattern — reduced alpha activity (theophylline-like) and increased beta-1 activity (amphetamine-like) — that is not reproduced by either metabolite alone[10]model confidence 97%
Verified

Abstract directly confirms the combined EEG pattern: theophylline-like alpha activity and amphetamine-like beta-1 activity, demonstrating fenetylline's own intrinsic mode of action.

Fenetylline has own intrinsic mode of action — not merely prodrug. EEG fingerprint resembles theophylline for alpha activity, amphetamine for beta1 activity.

checked by claude-sonnet-4-6 · May 11, 2026

legal status2 claims1verified1inconclusive
verifiedInternational scheduling occurred in 1986, when the World Health Organization added fenethylline to the Convention, citing addictive and hallucinogenic properties[2]model confidence 95%
Verified

Abstract directly confirms global prohibition in 1986 and that classification was due to addictive/hallucinogenic properties.

Classified Schedule 1 due to addictive/hallucinogenic properties. Global prohibition 1986.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveDespite universal prohibition, enforcement is challenged by the scale of clandestine production — principally in Syria — and consumption across the Arabian Peninsula.[13]model confidence 60%
Inconclusive

Abstract is a comprehensive review covering legislation and abuse patterns. However, the specific claims about Syrian production and Arabian Peninsula consumption as enforcement challenges are not in the abstract text and would need to be verified from the full text.

Comprehensive review of fenethylline covering chemistry, synthesis, pharmacology and toxicology, legislation, prevalence and use as drug of abuse.

checked by claude-sonnet-4-6 · May 11, 2026

05

Coverage & Gaps

effect links
61 links · 61 approved · 0 audited0/61 with evidence basis
interactions
10 approved pairs0/10 graded
06

Research Trail

substance-article pipeline-v5 May 11, 2026

StepSourceQueryResults
1database lookupPubChemfenethylline1 result, 1 selected
selection rationale

Chemical identity verification — confirms key structural data for the brief

2literature searchPubMedfenethylline pharmacology pharmacokinetics4 results, 4 selected
selection rationale

All directly relevant to pharmacokinetics and metabolism of fenethylline

3literature searchPubMedCaptagon amphetamine theophylline10 results, 8 selected
selection rationale

All directly relevant to fenethylline/captagon toxicity, cardiovascular effects, psychiatric effects, and abuse patterns

4literature searchPubMedfenethylline metabolism amphetamine theophylline prodrug3 results, 2 selected
selection rationale

Prodrug hypothesis and EEG characterization of fenethylline

5literature searchOpenAlexfenethylline captagon pharmacology10 results, 4 selected
selection rationale

High-citation comprehensive reviews and landmark papers on fenethylline

6document retrievalPubMedget article 270046211 result, 1 selected
selection rationale

Most comprehensive review available — covers chemistry, synthesis, pharmacology, toxicology, legislation, prevalence

7document retrievalPubMedget articles 38550445, 39512334, 36913784, 403973164 results, 4 selected
selection rationale

Narrative review, bibliometric, cardiovascular adverse effects, and BDNF neurotoxicity data

8literature searchPubMedcaptagon Syria production trafficking economy geopolitics1 result, 1 selected
selection rationale

Comprehensive regional context review

9clinical trial searchClinicalTrials.govfenethylline captagon0 results
selection rationale

Confirms absence of any current clinical trial activity

10web searchWebSearchfenethylline captagon history 1961 synthesis Degussa Germany first clinical use ADHD narcolepsy10 results, 2 selected
selection rationale

History and synthesis data not available in PubMed abstracts

11web searchWebSearchfenethylline DEA Schedule I 1981 Convention Psychotropic Substances 1986 UK Class A legal status10 results, 2 selected
selection rationale

Legal status verification for key jurisdictions

12document retrievallegislation.gov.ukfenethylline UK Misuse of Drugs Act 19861 result, 1 selected
selection rationale

Official UK legal source

13document retrievalWikiDocfenethylline legal status pharmacokinetics1 result, 3 selected
selection rationale

Concise legal/PK data not consolidated elsewhere

14web searchWebSearchfenethylline captagon WADA banned list sports doping physical properties melting point10 results, 2 selected
selection rationale

Physical property and doping context data

15web searchWebSearchcaptagon tramadol interaction fatal death serotonin syndrome case report10 results, 0 selected
selection rationale

Investigating the 'lethal' interaction severity listed in the brief - found no primary source to verify this

16literature searchPubMedcaptagon Jordan university students prevalence reasons use1 result, 1 selected
selection rationale

Prevalence and motivations for captagon use in student populations

Research document (raw, unedited pipeline output)
# Research Output: Fenethylline

---

## Chemical Identity

**Verified via PubChem CID 19527:**
- **Molecular formula:** C₁₈H₂₃N₅O₂
- **Molecular weight:** 341.4 g/mol
- **IUPAC name:** 1,3-dimethyl-7-[2-(1-phenylpropan-2-ylamino)ethyl]purine-2,6-dione (confirmed by PubChem API)
- **InChIKey:** NMCHYWGKBADVMK-UHFFFAOYSA-N
- **CAS number:** 3736-08-1 (free base); hydrochloride salt CAS: 1892-80-4
- **PubChem CID:** 19527 (free base); 102710 (hydrochloride)
- **Physical description:** White or off-white crystalline powder (hydrochloride form)
- **Melting point:** 227–229 °C (hydrochloride salt) [Ref 27]
- **Solubility:** Highly soluble in water and ethanol; sparingly soluble in nonpolar solvents [Ref 27]
- **SMILES:** Not retrieved via PubChem API; full SMILES available at PubChem CID 19527

**Brief data discrepancies:**
- The brief lists no SMILES, molecular formula, molecular weight, or InChIKey — all now confirmed from PubChem [Ref 26].
- Brief lists PubChem CID as blank — confirmed CID is **19527**.
- PubChem IUPAC matches the brief's systematic name exactly.

**Structural note:** Fenethylline is a hybrid molecule combining a theophylline (1,3-dimethylxanthine) moiety covalently linked via an ethylamine bridge to an amphetamine moiety. This structural linkage is the defining feature of its pharmacology (Nickel et al. 1986 [Ref 5]).

---

## Pharmacology

### Mechanism of Action

Fenethylline has a dual and complex mechanism of action that cannot be reduced to a simple prodrug model. While it metabolizes to both amphetamine and theophylline, multiple studies demonstrate that the intact parent molecule exerts its own intrinsic pharmacological activity (Nickel et al. 1986 [Ref 5]; Dimpfel et al. 1986 [Ref 9]).

**Amphetamine component (released on metabolism):**
- Acts as a substrate and releasing agent at the dopamine transporter (DAT) and norepinephrine transporter (NET), causing reverse transport of dopamine and norepinephrine into the synapse
- Agonist at trace amine-associated receptor 1 (TAAR1), enhancing dopaminergic signaling — identified as the primary driver of captagon's addictive potential and effects on irritability and aggression (Wu et al. 2019 [Ref 4])
- Serotonin transporter (SERT) activity is lower than at DAT/NET for amphetamine-class compounds, but relevant to interaction risk

**Theophylline component (released and also present as parent drug moiety):**
- Non-selective adenosine receptor antagonist (A₁ and A₂A subtypes)
- A₂A receptor blockade in the striatum attenuates behavioral sensitization caused by the amphetamine component, explaining why fenethylline may produce lower abuse potential than pure amphetamine (Wu et al. 2019 [Ref 4])
- Produces wakefulness, bronchodilation, and restlessness via adenosine antagonism

**Synergistic interaction:**
- Wu et al. (2019 [Ref 4]) demonstrated via systems pharmacology and molecular docking that the concurrent action of amphetamine (TAAR1 agonism) and theophylline (A₂A antagonism) produces faster and more potent psychoactive effects than either metabolite alone
- The parent molecule fenethylline thus produces a distinct pharmacological fingerprint that is neither purely amphetamine-like nor theophylline-like

**EEG evidence of intrinsic activity:**
- Telemetric EEG in freely moving rats showed fenethylline produces an EEG fingerprint combining reduced alpha activity (resembling theophylline) and increased beta-1 activity (resembling amphetamine), demonstrating the intact molecule acts on both target systems simultaneously (Dimpfel et al. 1986 [Ref 9])

**CYP2D6 interaction (metabolic):**
- The amphetamine metabolite competitively inhibits or blocks CYP2D6, which also metabolizes theophylline — this retards theophylline clearance and extends its duration of action, further amplifying the synergistic pharmacodynamic effect (Wu et al. 2019 [Ref 4])

**Cardiovascular pharmacology:**
- Original clinical advantage: fenethylline raises blood pressure less than equivalent doses of amphetamine, attributed to partial counterbalancing by theophylline's vasodilatory effects at therapeutic doses [Ref 27]
- At recreational/abuse doses: vasoconstrictive, pro-arrhythmic effects dominate (Gul et al. 2023 [Ref 12]; Gokdemir & Giden 2019 [Ref 13])

### Pharmacokinetics

**Published human data are limited.** No well-designed controlled human PK study has been published that provides Tmax, elimination half-life, or oral bioavailability for the parent fenethylline molecule.

**Metabolic fate (Yoshimura et al. 1988 [Ref 6] — 3 male human volunteers):**
- Route of metabolism: oxidative cleavage at two sites — one releasing the aminoethyl-theophylline fragment, one releasing amphetamine
- Pathway producing amphetamine predominates in humans (more so than in rat)
- **Major urinary metabolites (0-48 h):**
  - Carboxymethyl-theophylline: 39–43% of dose
  - Amphetamine: 23–33% of dose
  - Other minor metabolites: p-hydroxy-amphetamine, acetylaminoethyl-theophylline, aminoethyl-theophylline, hydroxyethyl-theophylline
- 7 additional metabolites identified by GC/MS beyond the 4 originally known (Rücker et al. 1988 [Ref 7])

**Metabolite fractions (secondary source [Ref 26]):**
- Amphetamine: approximately 24.5% of oral dose
- Theophylline: approximately 13.7% of oral dose

**Note on prodrug vs. independent pharmacology:** Only small fractions of the amphetamine theoretically available in the fenethylline molecule are released. Pharmacodynamic effects track more closely with parent compound plasma levels than with amphetamine metabolite levels (Nickel et al. 1986 [Ref 5]).

**Forensic/detection note:** Fenethylline concentrations in hair are 1.2–2.7 times higher than amphetamine concentrations; however, fenethylline disappears from urine faster than amphetamine [Ref 26]. This has implications for forensic detection.

**CYP enzyme involvement:** CYP2D6 involved in metabolism of the amphetamine moiety and potentially in theophylline clearance; CYP1A2 involved in theophylline metabolism (Kraemer & Maurer 2002 [Ref 8]).

**Precursor medication note:** Fenethylline is listed among drugs that produce amphetamine as a metabolite and can cause positive drug test results (Cody 2002 [Ref 17]).

---

## History

**Synthesis and early commercial history:**
- **1961:** First synthesized by chemists at **Degussa AG** (Deutsche Gold- und Silber-Scheideanstalt), a German pharmaceutical company, from amphetamine and 7-(2-chloroethyl)theophylline [Ref 27]
- Introduced to the West German market as a **50 mg tablet** in 1961 under the trade name **Captagon** (also marketed as Fitton, Biocapton, and Phenethylline) [Ref 27]
- **1964:** Strict prescription status requested in West Germany [Ref 27]
- Rationale for development: combining amphetamine stimulant properties with theophylline bronchodilator/methylxanthine effects in a single molecule with lower cardiovascular side effects [Ref 27]

**Clinical use period (1961–1986):**
- Approved for and used in:
  - Hyperkinetic disorders in children (what would now be called ADHD)
  - Narcolepsy
  - Depression
- Used across Europe and briefly in the United States (Pergolizzi et al. 2024 [Ref 2])
- Withdrawn from the US market due to side effects including hallucinations, visual distortions, and psychosis (Pergolizzi et al. 2024 [Ref 2])

**Regulatory withdrawal and prohibition:**
- **1981:** Placed on Schedule I in the United States — no accepted medical use (Van Hout & Wells 2016 [Ref 18])
- **1986:** Added to the Convention on Psychotropic Substances 1971 by the WHO, resulting in international prohibition in most signatory countries (Fong et al. 2024 [Ref 3]; Van Hout & Wells 2016 [Ref 18])
- **1986:** Added to the UK Misuse of Drugs Act 1971 as a Class C substance via the 1986 Modification Order [Ref 25]
- Commercial production effectively ceased in most countries by 1986

**Post-prohibition illicit history:**
- Early 2000s: Clandestine manufacture emerged in southeastern Europe (Slovenia, Serbia-Montenegro, Bulgaria, Turkey); stockpiling and trafficking through Turkey, Syria, and Jordan to the Arabian Peninsula observed by INCB and Interpol (Van Hout & Wells 2016 [Ref 18])
- By 2009: Estimated 700,000 counterfeit captagon pills consumed daily in Saudi Arabia alone (cited in the Middle East Drugs Bazaar review [Ref 20])
- **2013:** Syria superseded Lebanon as the premier producer and exporter of counterfeit captagon; 12.3 million pills seized near the Lebanon–Syria border that year (Van Hout & Wells 2016 [Ref 18])
- **2014:** 29.09 million captagon-branded pills seized in Dubai; Turkish authorities seized 7 million en route from Syria to Saudi Arabia (Van Hout & Wells 2016 [Ref 18])
- **2015:** Paris attacks context — captagon implicated in conflict zone use (Pergolizzi et al. 2024 [Ref 2])
- **2013+:** North Africa emerged as a new market (Katselou et al. 2016 [Ref 1])
- **Present:** Syria is a major global production hub; three-quarters of Saudi drug treatment patients are addicted to amphetamines, almost exclusively in the form of captagon (Katselou et al. 2016 [Ref 1])

**Important caveat on counterfeit captagon:** Since the mid-2000s, tablets marketed as "captagon" in the Arab world rarely contain genuine fenethylline. Counterfeit content routinely includes: amphetamine, methamphetamine, procaine, caffeine, quinine, ephedrine, metronidazole, theophylline, chlorphenamine, trimethoprim, chloroquine, lidocaine, and diphenhydramine (Van Hout & Wells 2016 [Ref 18]; Althobaiti et al. 2025 [Ref 10]). This distinction is critical for all epidemiological and toxicological data sourced from Arabic-language seizure or treatment literature post-2000.

---

## Subjective Effects

**Note:** No controlled human trial has characterized the subjective effects of genuine fenethylline specifically. The following is derived from: (a) clinical use literature from the 1960s–1980s; (b) qualitative studies of persons using captagon (which may be counterfeit); (c) case reports; and (d) combat/conflict use accounts. All data are labeled by source type.

### Stimulant/Cognitive Effects (qualitative reports from treatment populations)
- Stimulation, enhanced energy, and wakefulness — sought effects reported by users in Jordan (Wazaify et al. 2024 [Ref 16]) and Jordanian university students (Al Omari et al. 2022 [Ref 24])
- Focus and concentration enhancement — primary motivation for student use (Abdulfattah et al. 2024 [Ref 23])
- Euphoria and mood elevation
- Reduced fatigue — enabling sustained effort in academic or work contexts
- Sociability enhancement — described in qualitative user accounts

### Conflict/Combat Use (secondary accounts)
- Fearlessness, grandiosity, and reduced inhibition
- Ability to remain awake and active for extended periods — "can remain awake for days" (Van Hout & Wells 2016 [Ref 18])
- Described as "chemical courage" — producing energy, focus, and endurance in combat (Pergolizzi et al. 2024 [Ref 2])
- Dissociation from aversion and fear (Van Hout & Wells 2016 [Ref 18])

### Adverse/Unwanted Effects (dose-dependent)
- At higher or chronic doses: psychosis, paranoia, hallucinations, visual distortions — documented as withdrawal reason from US market (Pergolizzi et al. 2024 [Ref 2])
- Delusions — including morbid jealousy / infidelity delusions in 25.7% of a clinical psychosis population (101 patients; Shalaby et al. 2023 [Ref 14])
- Irritability, aggression (consistent with dopaminergic hyperstimulation; Wu et al. 2019 [Ref 4])
- Muscle tension, bruxism, appetite suppression, dry mouth, tachycardia — consistent with amphetamine-class profile

### Duration data (from brief, no contradicting published data found)
- **Onset:** 90–120 minutes (oral)
- **Total duration:** 3–4 hours (oral)
- *Note:* These values are not directly sourced to a specific published human study. They are consistent with amphetamine-class onset profiles following oral administration and with the metabolic cleavage timeline documented by Yoshimura et al. 1988 [Ref 6]. Flag for editorial review.

### Effect profile seeds (from brief) — research assessment:
All 13 seed effects in the brief are consistent with what is documented for amphetamine-type stimulants and are supported by the pharmacological mechanism (TAAR1 agonism, monoamine release, adenosine antagonism). However, no published human study has assigned specific intensity or frequency values to these effects for fenethylline specifically. Values will need to be inferred from the amphetamine class and validated qualitative sources.

---

## Safety & Toxicity

### Acute Cardiovascular Toxicity
- **Acute myocardial infarction:** Case report of a 23-year-old developing acute inferior MI after captagon tablet ingestion. Attributed to vasoconstriction and thrombus destabilization (Gokdemir & Giden 2019 [Ref 13]).
- **Brugada phenocopy:** Two cases of reversible type 1B Brugada ECG pattern associated with fenethylline abuse, resolving after discontinuation (Gul et al. 2023 [Ref 12]). Clinically significant because Brugada pattern predisposes to ventricular arrhythmia and sudden cardiac death.
- **QT prolongation and elevated ST segment:** Documented in rat models of captagon exposure and with captagon+azithromycin combination (Shehata et al. 2025 [Ref 11]). Human case data limited but consistent.
- **Cardiac biomarkers:** Elevated LDH and cardiac troponin I (cTnI) in rat captagon exposure models (Shehata et al. 2025 [Ref 11]).
- **Amphetamines and ACS:** Systematic review of amphetamine-type stimulants and cathinones links ATS class to acute coronary syndrome via mechanisms including coronary vasospasm, accelerated atherosclerosis, platelet activation, and direct cardiotoxicity (Gresnigt et al. 2023 [Ref 22]).

### Drug–Drug Cardiotoxicity
- **Captagon + azithromycin (rat model):** Synergistic cardiotoxicity via oxidative stress, inflammation (TNF-α, NF-κB, IL-1β, IL-6), and apoptosis (caspase-3, BAX). Reduced antioxidant enzymes (SOD, GSH, catalase). Elevated MDA and NO. Significant ECG changes including prolonged QT (Shehata et al. 2025 [Ref 11]).

### Psychiatric Toxicity
- **Captagon-induced psychosis:** Well-documented in clinical populations in Saudi Arabia. In a series of 101 male inpatients with captagon-induced psychosis (Shalaby et al. 2023 [Ref 14]):
  - Ages: 19–46 years (mean 30.87 ± 6.58 years)
  - Regular daily dose: 1–15 tablets
  - Maximum daily dose: 2–25 tablets
  - 25.7% developed delusions of infidelity (morbid jealousy)
  - Higher divorce rates among those with infidelity delusions (53.8%)
- **Visual hallucinations and psychosis** caused withdrawal of US approval (Pergolizzi et al. 2024 [Ref 2])

### Neurotoxicity (animal data — rat)
- Genuine fenethylline (50–100 mg/kg, rat) increases body temperature and locomotor activity
- Counterfeit captagon causes significantly greater hyperthermia and locomotor activation than genuine fenethylline, suggesting higher hyperthermia-related mortality risk from counterfeit pills (Althobaiti et al. 2025 [Ref 10])
- Counterfeit captagon (not genuine fenethylline) significantly reduces BDNF mRNA in the prefrontal cortex — suggesting long-term cognitive and neuroplasticity deficits (Althobaiti et al. 2025 [Ref 10])

### LD50 / Lethal Dose
- **No published LD50 data for fenethylline in animals or humans was identified.** The toxicology brief notes acute and chronic toxicity as "moderate" but cites these as inferred from pharmacological class. This requires a flag.
- Pergolizzi et al. (2024 [Ref 2]) state: "Captagon is addictive but no cases of direct captagon-associated mortality have been reported." This refers to genuine fenethylline; counterfeit captagon has a different risk profile.

### Therapeutic Index
- Not published for fenethylline.

---

## Harm Reduction

### Counterfeit Risk — Primary Harm Reduction Concern
The most critical harm reduction message for fenethylline/captagon is that virtually all pills currently sold as "captagon" in illicit markets **do not contain genuine fenethylline** and instead contain variable mixtures of amphetamines, local anesthetics (procaine, lidocaine), antihistamines, antibiotics (metronidazole, trimethoprim), caffeine, and other compounds (Van Hout & Wells 2016 [Ref 18]; Althobaiti et al. 2025 [Ref 10]). Counterfeit pills carry substantially greater toxicity risk than genuine fenethylline.

### Cardiovascular Risk Reduction
- Avoid use in any person with known cardiac conduction abnormalities, coronary artery disease, or Brugada syndrome history — risk of Brugada phenocopy and MI
- Avoid combining with QT-prolonging drugs (including azithromycin and other macrolide antibiotics) — documented synergistic cardiotoxicity (Shehata et al. 2025 [Ref 11])
- Monitor for chest pain, palpitations, irregular heartbeat — seek emergency care immediately

### Psychiatric Risk
- Psychosis risk is dose-dependent and increases with chronic use
- Persons with personal or family history of psychosis/schizophrenia are at substantially elevated risk
- Combat/conflict use at high doses for sustained periods represents an extreme risk exposure pattern

### Drug Interaction Avoidance
- **Tramadol:** Listed as "lethal" in the Psychedex database. Fenethylline-specific published evidence for this interaction was not found. The general mechanism: tramadol has serotonergic and opioid receptor activity; amphetamine-class stimulants have serotonergic activity. The combination may precipitate serotonin syndrome. This interaction severity rating requires editorial review and sourcing (see Gaps & Flags).
- **MAOIs:** Standard amphetamine-class contraindication; catastrophic serotonin syndrome risk — class-level caution applies to fenethylline
- **Other stimulants (caffeine, cocaine):** Additive cardiovascular and CNS effects
- **Antipsychotics:** May blunt dopaminergic effects but combination complicates psychiatric management

### Testing
- No commercial drug test specifically for fenethylline; immunoassay tests for amphetamines will cross-react with amphetamine metabolite. Fenethylline itself may not be detected on standard panels without targeted GC-MS or LC-MS analysis (de la Torre et al. 1996 [Ref cited in Kraemer & Maurer]).

---

## Tolerance & Dependence

### Dependence Liability
- Fenethylline was classified internationally under Schedule I/prohibited category in part because of documented addictive potential (Fong et al. 2024 [Ref 3])
- Original international prohibition in 1986 cited "addictive and hallucinogenic properties" (Fong et al. 2024 [Ref 3])
- Three of four patients treated for drug problems in Saudi Arabia are addicted to amphetamines, almost exclusively in the form of captagon (Katselou et al. 2016 [Ref 1])
- Amphetamine is identified as the primary driver of captagon addiction (TAAR1 agonism and dopaminergic sensitization; Wu et al. 2019 [Ref 4])

### Withdrawal
- Withdrawal symptoms documented in qualitative studies of captagon users in Jordan (Wazaify et al. 2024 [Ref 16]) — qualitative descriptions include crash/fatigue, depression, craving, and sleep disturbance consistent with amphetamine-class withdrawal
- No formal captagon-specific withdrawal severity scale or validated withdrawal characterization has been published
- The Fong et al. (2024 [Ref 3]) bibliometric review identifies "developing protocols for discontinuation" as a significant knowledge gap

### Tolerance
- No published controlled data on tolerance development rate for fenethylline specifically
- Reverse tolerance (sensitization) documented for amphetamine class in animal models; whether this applies to fenethylline's dual mechanism is not established
- CYP2D6 inhibition by the amphetamine metabolite may attenuate metabolic tolerance development by prolonging theophylline action

### Cross-Tolerance
- Expected cross-tolerance with other amphetamine-type stimulants based on shared TAAR1/DAT/NET mechanism — no fenethylline-specific cross-tolerance data published

---

## Interactions

### Tramadol [brief: lethal]
- No published case report or controlled study specifically documenting a fenethylline–tramadol lethal interaction was found during this research
- General mechanism for concern: tramadol inhibits serotonin and norepinephrine reuptake and is a weak opioid agonist; amphetamine-class stimulants (released as metabolite of fenethylline) promote monoamine release including serotonin
- The combination could precipitate **serotonin syndrome** — a potentially life-threatening condition
- **Flag for editorial review:** The "lethal" severity rating in the database cannot be verified against a published primary source. It may be extrapolated from general amphetamine + tramadol interaction data. Needs sourcing.

### Azithromycin [not in brief]
- Synergistic cardiotoxicity documented in rat model (Shehata et al. 2025 [Ref 11])
- Mechanism: additive QT prolongation, oxidative stress, inflammatory pathway activation
- Clinical relevance: combination should be considered dangerous; patients on azithromycin should not use captagon/fenethylline

### CYP2D6-metabolized drugs
- The amphetamine metabolite of fenethylline inhibits CYP2D6 (Wu et al. 2019 [Ref 4])
- Drugs with narrow therapeutic index metabolized by CYP2D6 (e.g., certain antidepressants, antipsychotics, opioids) may have elevated plasma levels when fenethylline is co-used

### Cannabis, Alcohol, GBL, GHB, Cocaine, Ketamine, Methoxetamine, Caffeine, PCP [brief: unknown or dangerous]
- No fenethylline-specific published interaction data found for any of these substances
- Class-level inferences apply from amphetamine pharmacology
- **PCP listed as "dangerous" in brief:** No published source verifying this rating specifically for fenethylline found; PCP + stimulants general pharmacodynamic antagonism/unpredictability is basis for concern
- All uncertain interaction severity ratings require flagging

---

## Legal Status

| Jurisdiction | Status | Date | Notes |
|---|---|---|---|
| **United States** | Schedule I (DEA) | 1981 | No accepted medical use [Ref 18, 26] |
| **United Kingdom** | Class C, Schedule 2 | 1986 | Added by Misuse of Drugs Act 1971 (Modification) Order 1986 [Ref 25] |
| **Canada** | Schedule III | — | Controlled Drugs and Substances Act [Ref 26] |
| **International** | Controlled | 1986 | Listed under 1971 Convention on Psychotropic Substances by WHO [Ref 3, 18] |
| **Australia** | Not confirmed | — | Expected prohibited substance; specific schedule not retrieved |
| **EU member states** | Generally prohibited | 1986+ | Via Convention on Psychotropic Substances adoption |
| **Saudi Arabia, Jordan, Syria** | Illegal but prevalent | — | Enforcement challenged by scale of counterfeit production [Ref 1, 15] |

**Anti-doping status:** As fenethylline metabolizes to amphetamine, use would result in a positive test for a WADA S6 prohibited stimulant. Fenethylline itself is explicitly prohibited as an amphetamine-type stimulant under WADA's Prohibited List.

---

## Clinical Trials

**No registered clinical trials were found on ClinicalTrials.gov for fenethylline or captagon.** The search returned zero results.

The Fong et al. (2024 [Ref 3]) bibliometric review identifies significant knowledge gaps in understanding captagon's mechanisms of action, metabolism, toxicology, and mortality risk, as well as the absence of treatment discontinuation protocols — indicating the current state of research is observational rather than interventional.

---

## Community Feedback Analysis

**No community feedback was submitted in Part A2 of the brief.**

No community feedback items to investigate or report.

---

## Gaps & Flags

### 🔴 Safety-Critical Flags (require editorial review before publication)

1. **Tramadol interaction severity ("lethal"):** No published primary source specifically documenting a fenethylline + tramadol lethal interaction was found. The rating appears to be extrapolated from general amphetamine-class + tramadol serotonin syndrome risk. *Editorial action required: source or downgrade severity level.*

2. **PCP interaction severity ("dangerous"):** No published source found verifying this rating specifically for fenethylline. *Editorial action required: source or downgrade.*

3. **Dose range not verified by published human study:** The dose ranges in the brief (Threshold 10mg, Light 20-40mg, Common 40-100mg, Strong 100-200mg, Heavy 200+mg) could not be verified against a controlled published study. The original clinical tablet was 50 mg. Clinical abuse populations use 1–15 tablets/day (50–750 mg range implied), consistent with a heavy dose range above 200 mg, but these are chronic abuse patterns, not single dose descriptions. *Flag: dose ranges are class-inferred + historical; no controlled human dose study exists.*

4. **Duration not verified by published human study:** Onset 90-120 min and total 3-4 hr are listed in the brief but no specific published human study confirms these figures for fenethylline. They are plausible based on oral absorption kinetics of amphetamine-class compounds. *Flag: duration is inferred, not source-confirmed.*

5. **No LD50 data:** No published LD50 for fenethylline in any species found. Acute and chronic toxicity ratings in the brief ("moderate") are stated as inferred from pharmacological class.

6. **Toxicity note in brief:** The brief itself flags: "Inferred from pharmacological class — not sourced from literature. Review recommended." Research confirms this is appropriate — no primary toxicology data found.

### 🟡 Data Gaps (informational)

7. **No published human pharmacokinetic study:** Tmax, elimination half-life, volume of distribution, protein binding, and oral bioavailability for the parent fenethylline molecule are not published. Only metabolic fate data in 3 volunteers exists (Yoshimura et al. 1988 [Ref 6]).

8. **Counterfeit vs. genuine distinction:** The majority of published literature post-2000 on captagon health effects concerns counterfeit pills, not genuine fenethylline. Effect, toxicity, and neurotoxicity data from this literature (particularly from Arab-region clinical populations) cannot be cleanly attributed to fenethylline itself. This distinction should be explicit in the article.

9. **No published cross-tolerance data:** Fenethylline-specific cross-tolerance with other amphetamine-class substances not established.

10. **Australia scheduling:** Not confirmed — likely prohibited but specific schedule not retrieved from official TGA source.

11. **No withdrawal characterization study:** Published withdrawal symptom data is limited to qualitative user reports from clinical populations (Wazaify et al. 2024 [Ref 16]). No formal withdrawal severity scale or timeline data available.

12. **SMILES not retrieved via API:** The PubChem API returned molecular formula but not SMILES. SMILES can be found directly at https://pubchem.ncbi.nlm.nih.gov/compound/19527.

13. **No published harm reduction protocol:** No specific evidence-based harm reduction protocol for fenethylline was found; harm reduction guidance should be extrapolated from amphetamine-class general guidance with explicit labeling.

14. **Stereochemistry:** Fenethylline contains a stereocenter at the amphetamine carbon. Published literature does not distinguish pharmacological differences between enantiomers for fenethylline itself; the racemic form appears to have been the marketed preparation. No enantiomer-specific data found.

15. **Interaction data gaps (all "unknown" entries in brief):** Cannabis, alcohol, caffeine, cocaine, GBL, GHB, ketamine, and methoxetamine interactions lack published fenethylline-specific data. These "unknown" ratings are appropriate given the literature.