Nifoxipam
Studies and references cited across this article, graded by evidence strength.
Inconclusive means the cited source neither confirms nor refutes the claim — a lower-confidence badge, not an error.
Data points an editor reviewed and accepted for publication.
Value Provenance
Dosing
oraltrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Threshold | 0.1 mg | 0.1 mg | low |
| Low | 0.25–0.5 mg | 0.25–0.5 mg | low |
| Common | 0.5–1 mg | 0.5–1 mg | low |
| Strong | 1–2 mg | 1–2 mg | low |
| Heavy | 2+ mg | 2+ mg | low |
| Editorial | Dose ranges from existing DB seed data, consistent with user-report data synthesized in Katselou et al. 2017 review. No controlled dose-finding study exists for nifoxipam. Values are entirely user-report derived. El Balkhi 2020 places nifoxipam in the lowest potency tier among designer BZDs, consistent with the 0.5–2 mg active range. | ||
ReasoningReasoningDose ranges from existing DB seed data, consistent with user-report data synthesized in Katselou et al. 2017 review. No controlled dose-finding study exists for nifoxipam. Values are entirely user-report derived. El Balkhi 2020 places nifoxipam in the lowest potency tier among designer BZDs, consistent with the 0.5–2 mg active range. Evidence basis: community_consensus_large | |||
Duration
oral
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Onsettrace | 45–120 minutes | 45–120 minutes | low |
| Editorial | Onset 45–120 minutes from Katselou et al. 2017 review, derived from user-report data. No controlled PK studies exist. | ||
ReasoningReasoningOnset 45–120 minutes from Katselou et al. 2017 review, derived from user-report data. No controlled PK studies exist. Evidence basis: community_consensus_large | |||
| Come uptrace | 30–60 minutes | 30–60 minutes | low |
| Editorial | Come-up estimated at 30–60 minutes based on onset-to-peak estimates from user reports and BZD class analogy (flunitrazepam). No nifoxipam-specific data. | ||
ReasoningReasoningCome-up estimated at 30–60 minutes based on onset-to-peak estimates from user reports and BZD class analogy (flunitrazepam). No nifoxipam-specific data. Evidence basis: structural_analogy | |||
| Peaktrace | 2–6 hours | 2–6 hours | low |
| Editorial | Peak duration estimated at 2–6 hours from BZD class analogy and user accounts of effect intensity. No controlled data for nifoxipam. Reference compound: flunitrazepam. | ||
ReasoningReasoningPeak duration estimated at 2–6 hours from BZD class analogy and user accounts of effect intensity. No controlled data for nifoxipam. Reference compound: flunitrazepam. Evidence basis: structural_analogy | |||
| Offsettrace | 4–24 hours | 4–24 hours | low |
| Editorial | Offset estimated at 4–24 hours based on the wide total duration range (10–75 hours) minus onset/come-up/peak. Reflects the high variability inherent in nifoxipam's pharmacokinetics. Reference: long-acting BZD class. | ||
ReasoningReasoningOffset estimated at 4–24 hours based on the wide total duration range (10–75 hours) minus onset/come-up/peak. Reflects the high variability inherent in nifoxipam's pharmacokinetics. Reference: long-acting BZD class. Evidence basis: structural_analogy | |||
| Totaltrace | 10–75 hours | 10–75 hours | low |
| Editorial | Total duration 10–75 hours from Katselou et al. 2017 review, synthesized from user-report data. The 7-fold range reflects dose variability, metabolic differences, and polysubstance confounders in the reporting population. Not derived from controlled PK measurement. | ||
ReasoningReasoningTotal duration 10–75 hours from Katselou et al. 2017 review, synthesized from user-report data. The 7-fold range reflects dose variability, metabolic differences, and polysubstance confounders in the reporting population. Not derived from controlled PK measurement. Evidence basis: community_consensus_large | |||
| After effectstrace | 6–24 hours | 6–24 hours | low |
| Editorial | Aftereffects estimated at 6–24 hours based on class inference from long-acting benzodiazepines (flunitrazepam, diazepam). No nifoxipam-specific data. Lingering cognitive impairment and possible rebound anxiety expected. | ||
ReasoningReasoningAftereffects estimated at 6–24 hours based on class inference from long-acting benzodiazepines (flunitrazepam, diazepam). No nifoxipam-specific data. Lingering cognitive impairment and possible rebound anxiety expected. Evidence basis: structural_analogy | |||
Safety
Toxicity Profiletrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Acute | moderate | moderate | low |
| Chronic | low | low | low |
| Organs Affected | pulmonary, neurological | pulmonary, neurological | low |
| Editorial | Acute: moderate — respiratory depression risk is real at high doses or with co-ingestants (STRIDA polysubstance cases, NPDS data showing 3% intubation across designer BZDs), but no nifoxipam-specific fatalities published. Discounted from 'high' per evidence discount rule (class extrapolation from flunitrazepam). Chronic: low — no chronic data; inferred from BZD class cognitive impairment literature, discounted one level from 'moderate'. Seed data values ('high/high') were internally contradictory with seed notes ('low toxicity') and are overridden. | ||
ReasoningReasoningAcute: moderate — respiratory depression risk is real at high doses or with co-ingestants (STRIDA polysubstance cases, NPDS data showing 3% intubation across designer BZDs), but no nifoxipam-specific fatalities published. Discounted from 'high' per evidence discount rule (class extrapolation from flunitrazepam). Chronic: low — no chronic data; inferred from BZD class cognitive impairment literature, discounted one level from 'moderate'. Seed data values ('high/high') were internally contradictory with seed notes ('low toxicity') and are overridden. Evidence basis: structural_analogy | |||
Dependence Profiletrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Physical | high | high | low |
| Psychological | high | high | low |
| Compulsive Redosing | moderate | moderate | low |
| Dose Escalation | high | high | low |
| Editorial | All dependence characterization inferred from flunitrazepam (parent compound) and benzodiazepine class data. No nifoxipam-specific dependence studies exist. Physical/psychological dependence rated 'high' per class inference. Compulsive redosing rated 'moderate' — slow onset (45–120 min) + long duration create a redosing window; user reports confirm this pattern. Dose escalation rated 'high' due to rapid tolerance buildup (within days). | ||
ReasoningReasoningAll dependence characterization inferred from flunitrazepam (parent compound) and benzodiazepine class data. No nifoxipam-specific dependence studies exist. Physical/psychological dependence rated 'high' per class inference. Compulsive redosing rated 'moderate' — slow onset (45–120 min) + long duration create a redosing window; user reports confirm this pattern. Dose escalation rated 'high' due to rapid tolerance buildup (within days). Evidence basis: structural_analogy | |||
Withdrawal Profiletrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Severity | life_threatening | life_threatening | low |
| Symptoms | anxiety, tremors, muscle spasticity, insomnia, tachycardia, hypertension, generalized seizures | anxiety, tremors, muscle spasticity, insomnia, tachycardia, hypertension, generalized seizures | low |
| Fatal | Yes | Yes | low |
| Medical Supervision | Required | Required | low |
| Editorial | Withdrawal characterization inferred from BZD class data. Onset delayed (24–72h, proposed 48h midpoint) relative to short-acting BZDs due to nifoxipam's 10–75h duration. Seizure risk makes withdrawal potentially life-threatening. Medical supervision required for discontinuation after sustained use. No nifoxipam-specific withdrawal data exist. | ||
ReasoningReasoningWithdrawal characterization inferred from BZD class data. Onset delayed (24–72h, proposed 48h midpoint) relative to short-acting BZDs due to nifoxipam's 10–75h duration. Seizure risk makes withdrawal potentially life-threatening. Medical supervision required for discontinuation after sustained use. No nifoxipam-specific withdrawal data exist. Evidence basis: structural_analogy | |||
Tolerance Profiletrace
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Buildup | rapid | rapid | low |
| Half-life | — | — | low |
| Full Reset | 10.5 days | 10.5 days | low |
| Cross-tolerances | benzodiazepines, alcohol, barbiturates, GABA-A positive allosteric modulators | benzodiazepines, alcohol, barbiturates, GABA-A positive allosteric modulators | low |
| Editorial | Buildup rate ('rapid', within days) from existing DB seed data and Katselou 2017 review, consistent with BZD class pharmacology. Full reset (10.5 days) from community consensus — not verified by controlled study. Cross-tolerances inferred from BZD class. All values are class-level inferences from flunitrazepam and benzodiazepine pharmacology. | ||
ReasoningReasoningBuildup rate ('rapid', within days) from existing DB seed data and Katselou 2017 review, consistent with BZD class pharmacology. Full reset (10.5 days) from community consensus — not verified by controlled study. Cross-tolerances inferred from BZD class. All values are class-level inferences from flunitrazepam and benzodiazepine pharmacology. Evidence basis: community_consensus_large | |||
Effects & Profile
Contraindications
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| respiratory Respiratory insufficiencytrace | absolute | absolute | low |
| Editorial | Class-level benzodiazepine contraindication. Respiratory depression is the primary lethal mechanism for all GABA-A PAMs, confirmed in STRIDA polysubstance cases involving nifoxipam. | ||
ReasoningReasoningClass-level benzodiazepine contraindication. Respiratory depression is the primary lethal mechanism for all GABA-A PAMs, confirmed in STRIDA polysubstance cases involving nifoxipam. | |||
| other Concurrent CNS depressant usetrace | absolute | absolute | medium |
| Editorial | Class-level benzodiazepine contraindication supported by STRIDA polysubstance case data (Bäckberg 2019) and Manchester 2018 review documenting fatal BZD-opioid combinations. | ||
ReasoningReasoningClass-level benzodiazepine contraindication supported by STRIDA polysubstance case data (Bäckberg 2019) and Manchester 2018 review documenting fatal BZD-opioid combinations. | |||
| hepatic Severe hepatic impairmenttrace | relative | relative | low |
| Editorial | Class-level benzodiazepine contraindication strengthened by nifoxipam-specific metabolism data (Meyer 2016, Pettersson Bergstrand 2019) showing hepatic phase I and II dependence. | ||
ReasoningReasoningClass-level benzodiazepine contraindication strengthened by nifoxipam-specific metabolism data (Meyer 2016, Pettersson Bergstrand 2019) showing hepatic phase I and II dependence. | |||
| pregnancy breastfeeding Pregnancy and lactationtrace | absolute | absolute | low |
| Editorial | Class-level benzodiazepine contraindication. No nifoxipam-specific reproductive data exist. Inferred from flunitrazepam and BZD class. | ||
ReasoningReasoningClass-level benzodiazepine contraindication. No nifoxipam-specific reproductive data exist. Inferred from flunitrazepam and BZD class. | |||
| neurological Myasthenia gravistrace | absolute | absolute | low |
| Editorial | Class-level benzodiazepine contraindication inferred from flunitrazepam and BZD class pharmacology. | ||
ReasoningReasoningClass-level benzodiazepine contraindication inferred from flunitrazepam and BZD class pharmacology. | |||
| other Acute narrow-angle glaucomatrace | relative | relative | low |
| Editorial | Class-level benzodiazepine contraindication. No nifoxipam-specific data. Low confidence — inferred from BZD class. | ||
ReasoningReasoningClass-level benzodiazepine contraindication. No nifoxipam-specific data. Low confidence — inferred from BZD class. | |||
| psychiatric History of paradoxical benzodiazepine reactionstrace | relative | relative | low |
| Editorial | Class-level benzodiazepine contraindication. Paradoxical reactions are an established BZD class phenomenon; prior occurrence with any BZD predicts recurrence. | ||
ReasoningReasoningClass-level benzodiazepine contraindication. Paradoxical reactions are an established BZD class phenomenon; prior occurrence with any BZD predicts recurrence. | |||
Timeline Phases
oral
| Field | Published | AI Proposed | Confidence |
|---|---|---|---|
| Onsettrace | 2700–7200 sec(i=0.15) | 2700–7200 sec(i=0.15) | low |
| Editorial | Onset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. | ||
ReasoningReasoningOnset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. Evidence basis: structural_analogy | |||
| Come uptrace | 1800–3600 sec(i=0.40) | 1800–3600 sec(i=0.40) | low |
| Editorial | Onset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. | ||
ReasoningReasoningOnset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. Evidence basis: structural_analogy | |||
| Peaktrace | 7200–21600 sec(i=1.00) | 7200–21600 sec(i=1.00) | low |
| Editorial | Onset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. | ||
ReasoningReasoningOnset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. Evidence basis: structural_analogy | |||
| Plateautrace | 14400–86400 sec(i=0.50) | 14400–86400 sec(i=0.50) | low |
| Editorial | Onset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. | ||
ReasoningReasoningOnset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. Evidence basis: structural_analogy | |||
| Afterglowtrace | 21600–86400 sec(i=0.15) | 21600–86400 sec(i=0.15) | low |
| Editorial | Onset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. | ||
ReasoningReasoningOnset (45–120 min) and total (10–75 h) from Katselou 2017 review of user-report data. Come-up (30–60 min), peak (2–6 h), offset/plateau (4–24 h), and afterglow (6–24 h) are Phase 1 inferences from BZD class analogy and user accounts. No controlled PK studies exist for nifoxipam. All non-onset/total phases are structural analogy from flunitrazepam and long-acting benzodiazepine class. Evidence basis: structural_analogy | |||
Dose Tier Summaries
At threshold doses (~0.1 mg oral), nifoxipam produces barely perceptible effects — a faint sense of relaxation and mild anxiety suppression that may be difficult to distinguish from placebo. Physical signs are absent or negligible; no measurable motor control impairment or sedation occurs. Cognitive function remains essentially intact. Users may notice a subtle background warmth or reduced baseline tension, but the effect is subclinical. One user report described 2 mg as producing "only a small relaxing feeling and body sedation," placing the threshold well below measurable subjective territory. The extremely slow onset (45–120 minutes) means threshold effects may take over an hour to become apparent, if they are noticed at all.
Threshold dose (0.1 mg) from existing DB/community consensus via Katselou 2017 review. Effect characterization inferred from BZD class pharmacology and user-report context. No controlled study data.
ReasoningReasoning
Threshold dose (0.1 mg) from existing DB/community consensus via Katselou 2017 review. Effect characterization inferred from BZD class pharmacology and user-report context. No controlled study data.
Evidence basis: community_consensus_large
Light doses (0.25–0.5 mg oral) produce mild anxiety suppression and gentle muscle relaxation. A soft sedative warmth settles over the body without producing overt drowsiness. Cognitive effects remain minimal — thought deceleration is subtle, and memory function is largely preserved. Physical effects include mild bodily heaviness and slight motor control impairment that most users would not notice in routine activities. Muscle relaxation is perceptible but does not significantly impair coordination. Functional impairment is low at this tier, but the compound's long duration (10–75 hours) means even light effects may persist well beyond expectation. The slow onset (45–120 minutes) creates a window where premature redosing is tempting but inadvisable.
Light dose range (0.25–0.5 mg) from existing DB/community consensus. Effect profile inferred from BZD class and El Balkhi 2020 potency ranking placing nifoxipam in lowest tier. No controlled data.
ReasoningReasoning
Light dose range (0.25–0.5 mg) from existing DB/community consensus. Effect profile inferred from BZD class and El Balkhi 2020 potency ranking placing nifoxipam in lowest tier. No controlled data.
Evidence basis: community_consensus_large
Common doses (0.5–1 mg oral) produce clear anxiolysis, moderate sedation, and noticeable muscle relaxation. Cognitive euphoria may emerge — though it is notably less prominent than with etizolam or high-potency designer benzodiazepines. Emotional suppression flattens affective reactivity. Thought deceleration and analysis suppression become apparent. Amnesia may begin at this tier, particularly toward the upper end. Disinhibition is noticeable — users may behave or communicate in ways inconsistent with their sober baseline. Motor control impairment affects fine coordination. One user report described cumulative 8 mg as producing "benzodiazepine-like sedation and anti-anxiety effects along with slight euphoria" — common doses produce these effects at lower intensity. Delusions of sobriety are possible: users may significantly underestimate their level of impairment, increasing redosing risk during the long onset window.
Common dose range (0.5–1 mg) from existing DB/Katselou 2017 user-report data. Effect characterization from El Balkhi 2020 (euphoria less than etizolam) and BZD class pharmacology.
ReasoningReasoning
Common dose range (0.5–1 mg) from existing DB/Katselou 2017 user-report data. Effect characterization from El Balkhi 2020 (euphoria less than etizolam) and BZD class pharmacology.
Evidence basis: community_consensus_large
Strong doses (1–2 mg oral) produce pronounced sedation with hypnotic potential, significant anterograde amnesia, and marked disinhibition. Motor control is substantially impaired — coordination difficulties are obvious. Delusions of sobriety are likely: users at this tier commonly believe they are less impaired than they actually are. Cognitive effects are prominent: thought disorganization, dense memory suppression, and motivation suppression dominate. Emotional suppression is marked. Cognitive euphoria, when present, occurs early and gives way to heavy sedation. Analysis suppression makes complex reasoning difficult. The extended duration becomes particularly consequential at this tier — effects may persist 24–48 hours or longer. Compulsive redosing risk is elevated because users may not recognize the magnitude of initial effects until well past the onset window.
Strong dose range (1–2 mg) from existing DB/Katselou 2017. Effect characterization from BZD class pharmacology, STRIDA intoxication case profiles, and user-report data.
ReasoningReasoning
Strong dose range (1–2 mg) from existing DB/Katselou 2017. Effect characterization from BZD class pharmacology, STRIDA intoxication case profiles, and user-report data.
Evidence basis: community_consensus_large
Heavy doses (2+ mg oral) produce deep sedation approaching stupor, with loss of consciousness possible. Dense anterograde amnesia prevents recall of events during the intoxicated period. Respiratory depression risk is meaningfully elevated, particularly in combination with any other CNS depressant. Motor control is severely impaired — walking may be difficult or impossible. Cognitive function is profoundly suppressed. Speech is slurred and incoherent. The user is functionally incapacitated for an extended period, potentially 48–75 hours given the compound's extreme duration variability. This tier carries the highest risk of medical emergency. Flumazenil reversal is effective but may require repeated administration given the extended duration. Users switching from high-potency designer benzodiazepines (flubromazolam, clonazolam) may misjudge nifoxipam's lower potency and take unexpectedly large doses.
Heavy dose (2+ mg) from existing DB/Katselou 2017. Risk characterization from STRIDA intoxication cases, NPDS data (36% hospitalization, 22% ICU, 3% intubation across designer BZDs), and BZD class pharmacology.
ReasoningReasoning
Heavy dose (2+ mg) from existing DB/Katselou 2017. Risk characterization from STRIDA intoxication cases, NPDS data (36% hospitalization, 22% ICU, 3% intubation across designer BZDs), and BZD class pharmacology.
Evidence basis: community_consensus_large
History
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.
Sources
- [1]strongSedative-Hypnotic Agents That Impact Gamma-Aminobutyric Acid Receptors: Focus on Flunitrazepam, Gamma-Hydroxybutyric Acid, Phenibut, and SelankDoyno CR, White CM · 2021 · Journal of Clinical Pharmacology
- [2]weakMetabolites replace the parent drug in the drug arena - PMC full textKatselou M et al. · 2017linkno claims checked
- [3]strongMetabolites replace the parent drug in the drug arena. The cases of fonazepam and nifoxipam.Katselou M, Papoutsis I, Nikolaou P, Spiliopoulou C, Athanaselis S · 2017 · Forensic toxicology
- [4]moderateDesigner benzodiazepines' pharmacological effects and potencies: How to find the informationEl Balkhi S, Monchaud C, Herault F, Geniaux H, Saint-Marcoux F · 2020 · Journal of Psychopharmacology
- [5]strongCurrent Therapeutic Strategies for the Management of Benzodiazepine (BZD) Withdrawal Syndrome: A Review.Saini S, Tahlan S, Minocha N · 2024 · Current topics in medicinal chemistry
- [6]moderateThe emergence of new psychoactive substance (NPS) benzodiazepines: A review.Manchester KR, Lomas EC, Waters L, Dempsey FC, Maskell PD · 2018 · Drug testing and analysis
- [7]moderateDesigner benzodiazepines versus prescription benzodiazepines: can structural relation predict the next step?Moustafa RE, Tarbah F, Saeed HS, Sharif SI · 2021 · Critical Reviews in Toxicology
- [8]moderateDesigner benzodiazepines: a report of exposures recorded in the National Poison Data System, 2014-2017.Carpenter JE, Murray BP, Dunkley C, Kazzi ZN, Gittinger MH · 2019 · Clinical Toxicology
- [9]weakThe Misuse of Drugs (Amendment) (England, Wales and Scotland) Regulations 2017 (SI 2017/631)UK Parliament · 2017linkno claims checked
- [10]moderateDesigner benzodiazepines: A new challengeMoosmann B, King LA, Auwärter V · 2015 · World Psychiatry
- [11]weakNifoxipam physical properties - Cayman Chemical / ChemSpiderVarious chemical suppliers · 2024linkno claims checked
- [12]moderateIdentification of main human urinary metabolites of the designer nitrobenzodiazepines clonazolam, meclonazepam, and nifoxipam by nano-liquid chromatography-high-resolution mass spectrometry for drug testing purposes.Meyer MR, Bergstrand MP, Helander A, Beck O · 2016 · Analytical and bioanalytical chemistry
- [13]moderateCharacterization and identification of eight designer benzodiazepine metabolites by incubation with human liver microsomes and analysis by a triple quadrupole mass spectrometer.El Balkhi S, Chaslot M, Picard N, Dulaurent S, Delage M, Mathieu O, Saint-Marcoux F · 2017 · International Journal of Legal Medicine
- [14]moderateIn vitro glucuronidation of designer benzodiazepines by human UDP-glucuronyltransferasesPettersson Bergstrand M, Richter LHJ, Maurer HH, Wagmann L, Meyer MR · 2019 · Drug Testing and Analysis
- [15]moderateUrine analysis of 28 designer benzodiazepines by liquid chromatography-high-resolution mass spectrometryPettersson Bergstrand M, Beck O, Helander A · 2018 · Clinical Mass Spectrometry
- [16]moderateFast and Sensitive Method for the Determination of 17 Designer Benzodiazepines in Hair by Liquid Chromatography-Tandem Mass SpectrometryDeFreitas L, Fonseca Pego AM, Kronstrand R, Lendoiro E, de Castro-Rios A, Concheiro M · 2022 · Journal of Analytical Toxicology
- [17]moderateDetectability of designer benzodiazepines in CEDIA, EMIT II Plus, HEIA, and KIMS II immunochemical screening assaysPettersson Bergstrand M, Helander A, Hansson T, Beck O · 2017 · Drug Testing and Analysis
- [18]moderateThe blood-to-plasma ratio and predicted GABAA-binding affinity of designer benzodiazepinesManchester KR, Waters L, Haider S, Maskell PD · 2022 · Forensic Toxicology
- [19]moderateOccurrence and time course of NPS benzodiazepines in Sweden - results from intoxication cases in the STRIDA project.Bäckberg M, Pettersson Bergstrand M, Beck O, Helander A · 2019 · Clinical Toxicology
- [20]moderateThe Evolution Toward Designer Benzodiazepines in Drug-Facilitated Sexual Assault CasesPérez Orts M, van Asten A, Köhler I · 2023 · Journal of Analytical Toxicology
- [21]moderateDrug-facilitated crime: A review of findings between 2019 and 2023Hessler MR, Kacinko SL, Logan BK · 2025 · Journal of forensic sciences
- [22]weak
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 claims2verified2partial4inconclusive
verifiedDependence liability is inferred from flunitrazepam and class-level benzodiazepine data: physical and psychological dependence develop with sustained use, and abrupt cessation carries seizure risk[5]model confidence 85%
Abstract directly confirms life-threatening seizures on abrupt BZD cessation, supporting the seizure risk component of the claim.
BZD withdrawal: tremors, muscle spasticity, life-threatening seizures on abrupt cessation; review of mechanisms and management strategies.
checked by claude-sonnet-4-6 · May 9, 2026
partialAmong designer benzodiazepines, nifoxipam occupies the lowest potency tier — ranked alongside deschloroetizolam, metizolam, and pyrazolam — with an oral active dose range of 0.5–2 mg and an unusually protracted duration of action spanning 10–75 hours.[4]model confidence 80%
Abstract confirms nifoxipam ranked among least potent DBZDs, but the specific dose range (0.5–2 mg) and duration (10–75 hours) are not mentioned, nor are the specific companion compounds in the tier.
Nifoxipam ranked among least potent DBZDs. Potency score derived; structural analysis confirms ranking except nifoxipam anomalous.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveAmong designer benzodiazepines, nifoxipam occupies the lowest potency tier — ranked alongside deschloroetizolam, metizolam, and pyrazolam — with an oral active dose range of 0.5–2 mg and an unusually protracted duration of action spanning 10–75 hours.[3]model confidence 75%
This comprehensive review covers nifoxipam pharmacology broadly but the abstract does not confirm potency tier ranking, dose range, or duration. Data may be in full text.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedThe existing evidence base consists almost entirely of forensic toxicology case reports, analytical chemistry methods, and a single comprehensive review.[3]model confidence 75%
This paper IS the single comprehensive review referenced. The abstract describes a review covering chemistry, synthesis, pharmacology, toxicology, biotransformation, and analysis, consistent with the claim's characterisation of the evidence base.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveAs a benzodiazepine, nifoxipam is presumed to act at the α/γ₂ subunit interface of GABA-A receptors, increasing chloride channel opening frequency in response to endogenous GABA[1]model confidence 70%
Abstract confirms flunitrazepam (parent) has high GABA-A receptor affinity, but the specific α/γ₂ subunit interface and chloride channel opening frequency mechanism are not addressed in the abstract.
Flunitrazepam has greater potency and higher affinity for GABA-A receptor than most BZDs.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveThe subjective profile is qualitatively typical of benzodiazepines — anxiolysis, sedation, muscle relaxation, and amnesia — though euphoria is notably less prominent than in etizolam or other high-potency designer analogs.[4]model confidence 70%
Abstract is based on trip reports and covers potency ranking, but specific effects (anxiolysis, sedation, amnesia) and euphoria comparison to etizolam are not confirmed in the abstract.
Analysis of 197 trip reports for 10 DBZDs including nifoxipam. Nifoxipam ranked among least potent DBZDs.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveNo controlled toxicity data exist for nifoxipam in any species — no LD₅₀, no therapeutic index, and no lethal overdose attributed solely to this compound has been published. Respiratory depression constitutes the primary life-threatening risk, particularly in combination with other CNS depressants[3]model confidence 65%
Abstract describes a comprehensive review covering toxicology but does not explicitly confirm absence of controlled toxicity data or identify respiratory depression as primary risk. Full text may contain this information.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
partialNo controlled toxicity data exist for nifoxipam in any species — no LD₅₀, no therapeutic index, and no lethal overdose attributed solely to this compound has been published. Respiratory depression constitutes the primary life-threatening risk, particularly in combination with other CNS depressants[6]model confidence 75%
Abstract directly supports respiratory depression risk from BZD+opioid combination. However, the absence of controlled toxicity data claim is not addressed, making the full multi-assertion claim only partially supported.
illicit BZDs combined with opiates lead to respiratory depression and death.
checked by claude-sonnet-4-6 · May 9, 2026
history6 claims3verified3inconclusive
inconclusiveNifoxipam originated not as a drug designed for independent use but as a known metabolite of flunitrazepam (Rohypnol), a potent nitrobenzodiazepine first synthesized in 1963 by Leo Sternbach and colleagues at Hoffmann-La Roche[7]model confidence 70%
Abstract is about structural modifications in designer BZDs and does not address the historical synthesis of flunitrazepam (1963, Sternbach, Hoffmann-La Roche). The review's scope may cover this but is not confirmed.
Review of designer BZDs; structural modifications can lead to stronger effects, more toxicity, longer duration; postmortem redistribution differences.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedFlunitrazepam undergoes sequential N-demethylation and 3-hydroxylation in vivo to yield nifoxipam (3-hydroxy-N-desmethylflunitrazepam), an active metabolite that retains pharmacological activity at the GABA-A receptor[3]model confidence 97%
Abstract directly confirms nifoxipam as 3-hydroxy-desmethylflunitrazepam and active metabolite of flunitrazepam.
Nifoxipam (3-hydroxy-desmethylflunitrazepam) are benzodiazepine derivatives and active metabolites of flunitrazepam.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveThe first confirmed seizure occurred in April 2014 in Visby, Sweden, where 20 brown tablets were identified via GC-MS, LC-MS, and nuclear magnetic resonance spectroscopy.[3]model confidence 70%
Abstract confirms European seizures in 2014–2016 but does not specify April 2014, Visby, 20 tablets, or GC-MS/NMR analytical methods. Full text likely contains these details.
Seized in powder and tablet forms in Europe between 2014 and 2016.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveBetween December 2014 and July 2015, seizures expanded across multiple European jurisdictions: Finland (four round, light-brown tablets marked "Nifoxipam 1 MG," sent from the United Kingdom), Norway, Slovenia, Denmark, and France[3]model confidence 70%
Abstract confirms European seizures 2014–2016 but does not confirm specific countries, dates, or tablet descriptions. These details are likely in the full text.
Seized in powder and tablet forms in Europe between 2014 and 2016.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedMoosmann et al. documented nifoxipam in 2015 as one of five newly available designer benzodiazepines sold online, alongside clonazolam, deschloroetizolam, flubromazolam, and meclonazepam.[10]model confidence 97%
Direct match: abstract confirms nifoxipam listed among 5 recently available designer BZDs in 2015.
Nifoxipam listed among 5 recently available designer BZDs in 2015.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedTrafficking was primarily confined to Europe during this initial period, with minimal data from the United States, Australia, or Japan[3]model confidence 75%
Abstract confirms European seizures (powder and tablet forms) as the documented trafficking pattern, consistent with European-focused distribution.
Seized in powder and tablet forms in Europe between 2014 and 2016.
checked by claude-sonnet-4-6 · May 9, 2026
chemistry3 claims1verified1partial1inconclusive
verifiedThe compound is the N-desmethyl-3-hydroxy derivative of flunitrazepam — differing from the parent by loss of the N-methyl group at position 1 and addition of a hydroxyl group at position 3.[3]model confidence 95%
The chemical name '3-hydroxy-desmethylflunitrazepam' directly confirms both structural modifications described.
Nifoxipam (3-hydroxy-desmethylflunitrazepam) are benzodiazepine derivatives and active metabolites of flunitrazepam.
checked by claude-sonnet-4-6 · May 9, 2026
partialThe 3-hydroxyl group increases hydrophilicity relative to flunitrazepam, a modification that typically reduces blood-brain barrier penetration and may partially explain nifoxipam's lower observed potency.[4]model confidence 80%
Abstract confirms nifoxipam's lower observed potency but explicitly notes the structural analysis result is anomalous for nifoxipam, undermining the proposed structural/hydrophilicity explanation.
structural analysis confirms ranking except nifoxipam anomalous.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveOther names encountered in the literature include 3-hydroxydesmethylflunitrazepam, 3-hydroxy-N-desmethylflunitrazepam, DP-370, and DP370.[3]model confidence 70%
Abstract confirms the IUPAC-style name '3-hydroxy-desmethylflunitrazepam' but DP-370/DP370 designations are not mentioned. Full text likely contains the complete synonym list.
Nifoxipam (3-hydroxy-desmethylflunitrazepam) are benzodiazepine derivatives.
checked by claude-sonnet-4-6 · May 9, 2026
pharmacology20 claims14verified6inconclusive
verified7-acetaminonifoxipam — most abundant urinary metabolite; best detection target[12]model confidence 97%
Direct match: abstract states 7-acetaminonifoxipam is the main urinary target.
main urinary target: 7-acetaminonifoxipam.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedParent compound glucuronide — significant secondary target[12]model confidence 90%
Abstract confirms parent compound glucuronide conjugate is also excreted in urine.
also excreted as glucuronic acid conjugate of parent.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedParent compound glucuronide — significant secondary target[14]model confidence 80%
Abstract confirms glucuronide conjugates of nifoxipam are produced in in vitro glucuronidation assays, supporting existence of this metabolite.
Glucuronide conjugates of nifoxipam only detected in pHLM.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedParent compound (unchanged) — detected in routine testing and acute intoxication cases[15]model confidence 98%
Direct match: abstract confirms nifoxipam detected in patient urine from both routine testing and acute intoxication cases.
Nifoxipam detected in patient urine samples from routine drug testing and acute intoxication cases via LC-HRMS.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedNifoxipam displays an unusual UDP-glucuronosyltransferase (UGT) profile: glucuronide conjugates were detected only in pooled human liver microsomes (pHLM) and not when 13 individual UGT enzymes were tested separately[14]model confidence 97%
Direct match with abstract findings.
Glucuronide conjugates of nifoxipam only detected in pHLM, not attributable to individual UGTs, suggesting dimer complexes.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveNifoxipam is a positive allosteric modulator (PAM) of GABA-A receptors, acting at the classical benzodiazepine binding site located at the interface of α and γ₂ subunits[1]model confidence 70%
Abstract confirms flunitrazepam's GABA-A receptor affinity but does not confirm the PAM mechanism or the specific α/γ₂ subunit interface for nifoxipam.
Flunitrazepam has greater potency and higher affinity for GABA-A receptor than most BZDs.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveNifoxipam is a positive allosteric modulator (PAM) of GABA-A receptors, acting at the classical benzodiazepine binding site located at the interface of α and γ₂ subunits[3]model confidence 70%
Abstract covers nifoxipam pharmacology broadly but does not specifically confirm PAM mechanism or α/γ₂ subunit interface details.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveLike all benzodiazepines, nifoxipam does not directly activate the chloride channel; it increases the frequency of channel opening events in response to GABA binding, thereby enhancing inhibitory neurotransmission throughout the central nervous system[1]model confidence 70%
Abstract does not address the specific chloride channel opening frequency mechanism. The GABA-A receptor context is mentioned but the mechanistic detail is absent.
Flunitrazepam has greater potency and higher affinity for GABA-A receptor than most BZDs.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedFlunitrazepam demonstrates greater potency and higher GABA-A receptor affinity than most standard benzodiazepines[1]model confidence 98%
Direct verbatim match with the abstract.
Flunitrazepam has greater potency and higher affinity for GABA-A receptor than most BZDs.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedNifoxipam, as the N-desmethyl-3-hydroxy metabolite, retains pharmacological activity at this site, though the magnitude of its intrinsic efficacy and receptor affinity relative to the parent compound have not been quantified.[3]model confidence 80%
Abstract confirms nifoxipam is an active metabolite of flunitrazepam, supporting retained pharmacological activity. The unquantified magnitude is consistent with the review not reporting specific affinity values.
Nifoxipam (3-hydroxy-desmethylflunitrazepam) are benzodiazepine derivatives and active metabolites of flunitrazepam.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveNo substance-specific binding affinity data (Ki, IC₅₀, or EC₅₀) have been published for nifoxipam at any receptor target[3]model confidence 65%
Abstract is a comprehensive pharmacology review but does not explicitly confirm the absence of binding data. The absence of such values in the abstract is suggestive but not definitive.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveOnset of effects after oral administration is 45–120 minutes[3]model confidence 65%
Abstract does not mention onset timing. Data may be in the full text of the review.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveTotal duration of subjective effects spans approximately 10–75 hours[3]model confidence 65%
Abstract does not mention duration of effects. Data may be in the full text of the review.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedNifoxipam is itself an active metabolite of flunitrazepam (the N-desmethyl-3-hydroxy derivative)[3]model confidence 98%
Direct match: abstract explicitly identifies nifoxipam as 3-hydroxy-desmethylflunitrazepam and active metabolite of flunitrazepam.
Nifoxipam (3-hydroxy-desmethylflunitrazepam) are benzodiazepine derivatives and active metabolites of flunitrazepam.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedThe primary metabolic pathway involves nitro-reduction of the 7-nitro group to yield 7-aminonifoxipam, followed by acetylation to 7-acetaminonifoxipam — the most abundant urinary metabolite and the recommended primary detection target for forensic and clinical drug testing[12]model confidence 90%
Abstract confirms 7-acetaminonifoxipam as the main urinary target. The full metabolic pathway detail (nitro-reduction → 7-aminonifoxipam → acetylation) is consistent with extensive metabolism described.
Nifoxipam extensively metabolized; main urinary target: 7-acetaminonifoxipam.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedAdditional phase I metabolites identified through human liver microsome (HLM) incubation include denitro-, mono-hydroxylated, di-hydroxylated, and desmethyl variants.[13]model confidence 97%
Direct match: abstract confirms HLM incubation identifying denitro-, mono- or di-hydroxylated and desmethyl forms across 8 DBZDs including nifoxipam.
Nifoxipam incubated with HLMs; 26 metabolites identified across 8 DBZDs including denitro-, mono- or di-hydroxylated and desmethyl forms.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedGlucuronidation of the parent compound produces a significant urinary metabolite[14]model confidence 80%
Abstract confirms glucuronide conjugates of nifoxipam are detected (in pHLM), supporting the existence of this metabolic pathway.
Glucuronide conjugates of nifoxipam only detected in pHLM, not attributable to individual UGTs, suggesting dimer complexes.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedThis contrasts sharply with most other designer benzodiazepines (clonazolam, deschloroetizolam, etizolam, flubromazolam, metizolam), which are glucuronidated exclusively by UGT1A4[14]model confidence 90%
Abstract confirms most designer BZDs are glucuronidated by UGT1A4, directly supporting the contrast claim.
Most DBZs glucuronidated by UGT1A4.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedHair testing — validated LC-MS/MS methods exist for nifoxipam detection in hair[16]model confidence 98%
Direct match: abstract confirms validated LC-MS/MS hair method for 17 designer BZDs including nifoxipam.
Validated LC-MS/MS hair method for 17 designer BZDs including nifoxipam; LOQ 5-25 pg/mg.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedStandard immunoassay benzodiazepine screens show high cross-reactivity with nifoxipam, though confirmatory LC-MS/MS or LC-HRMS is required for definitive identification.[17]model confidence 88%
High cross-reactivity directly confirmed. Confirmatory testing requirement is standard practice inference consistent with immunoassay limitations.
Nifoxipam showed high cross-reactivity in standard immunoassay BZD screening. KIMS II and CEDIA showed highest reactivity.
checked by claude-sonnet-4-6 · May 9, 2026
neuroscience4 claims1verified3inconclusive
inconclusiveAt supratherapeutic doses, progressive cortical inhibition produces cognitive impairment, anterograde amnesia, and eventually loss of consciousness — the dose-response continuum underlying both therapeutic use and overdose toxicity.[6]model confidence 65%
Abstract covers NPS benzodiazepine review broadly but does not address the dose-response continuum of cortical inhibition, cognitive impairment, or amnesia.
Comprehensive review of NPS benzodiazepines; large differences in PK parameters; illicit BZDs combined with opiates lead to respiratory depression and death.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveThe anxiolytic effect is mediated primarily through α₂- and α₃-containing GABA-A receptors concentrated in the amygdala and limbic structures, reducing fear-circuit activation and producing the subjective experience of anxiety suppression. Sedation and amnesia are mediated through α₁-containing receptors in the cortex and hippocampus, respectively. Muscle relaxation involves spinal cord and brainstem α₂/α₃ receptors.[1]model confidence 65%
Abstract discusses GABA-A receptor pharmacology for flunitrazepam broadly but does not address subunit-specific effect mapping (α₁, α₂, α₃) for any effect domain.
Flunitrazepam has greater potency and higher affinity for GABA-A receptor than most BZDs.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveNifoxipam's relatively modest euphoria may reflect lower VTA disinhibition secondary to its reduced overall potency.[4]model confidence 65%
Abstract confirms lower potency but does not address VTA disinhibition or euphoria mechanism. This is a speculative mechanistic inference not verifiable from the abstract.
Nifoxipam ranked among least potent DBZDs.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedWhat is nifoxipam's binding affinity at GABA-A receptor subtypes? Without Ki values, potency ranking relies entirely on subjective report analysis. Direct radioligand binding or fluorescence polarization assays could resolve the anomalous potency discrepancy identified by El Balkhi et al.[4]model confidence 90%
Abstract directly supports both the reliance on subjective report analysis for potency ranking and the anomalous potency discrepancy that would need resolution.
Nifoxipam ranked among least potent DBZDs. Potency score derived; structural analysis confirms ranking except nifoxipam anomalous.
checked by claude-sonnet-4-6 · May 9, 2026
receptor pharmacology6 claims3verified3inconclusive
inconclusiveNifoxipam acts at the classical benzodiazepine binding site on GABA-A receptors (α/γ₂ interface)[1]model confidence 65%
Abstract confirms GABA-A receptor involvement for flunitrazepam but does not specifically address the α/γ₂ interface for nifoxipam.
Flunitrazepam has greater potency and higher affinity for GABA-A receptor than most BZDs.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveNo published binding affinity data (Ki, IC₅₀, EC₅₀, or koff) exist for nifoxipam at any receptor target[3]model confidence 65%
Abstract describes a comprehensive pharmacology review but absence of binding data cannot be confirmed from abstract alone.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedIts parent compound flunitrazepam is among the highest-affinity benzodiazepines at this site, but no direct measurement of nifoxipam's affinity has been published.[1]model confidence 90%
Abstract directly confirms flunitrazepam has greater potency and higher affinity than most BZDs. Absence of nifoxipam-specific data is consistent with the review's focus on flunitrazepam.
Flunitrazepam has greater potency and higher affinity for GABA-A receptor than most BZDs.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveThe structurally related compound fonazepam (N-desmethylflunitrazepam) — the immediate metabolic precursor to nifoxipam in the flunitrazepam biotransformation pathway — was reported with a binding activity log IC₅₀ = 0.176 (predicted value 0.565) in one source cited by Katselou et al. Assay conditions and units were not fully specified, limiting interpretation.[3]model confidence 70%
Abstract confirms fonazepam as a related metabolite but specific IC₅₀ values are not in the abstract and cannot be verified.
Fonazepam (desmethylflunitrazepam) and nifoxipam (3-hydroxy-desmethylflunitrazepam) are benzodiazepine derivatives and active metabolites of flunitrazepam.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedManchester et al. applied QSAR modelling to predict GABA-A receptor binding affinity for a panel of designer benzodiazepines including nifoxipam; the specific predicted value was not reported in the available abstract.[18]model confidence 95%
Abstract directly confirms QSAR modelling of GABA-A receptor binding affinity for designer BZDs including nifoxipam. The claim that the specific value is not in the abstract is also accurate.
QSAR-modelled GABA-A receptor binding affinity and blood-to-plasma ratio data for designer BZDs including nifoxipam.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedEl Balkhi et al. classified nifoxipam in the lowest potency tier among 10 designer benzodiazepines analyzed, alongside deschloroetizolam, metizolam, and pyrazolam[4]model confidence 85%
Abstract confirms nifoxipam ranked among least potent DBZDs in a 10-DBZD analysis. Specific tier companions not confirmed in abstract but core classification is.
Analysis of 197 trip reports for 10 DBZDs including nifoxipam. Nifoxipam ranked among least potent DBZDs.
checked by claude-sonnet-4-6 · May 9, 2026
pharmacokinetic detail7 claims4verified3inconclusive
inconclusiveOne user report documented euphoria onset within 10–15 minutes when 1 mg was taken with alcohol, suggesting that ethanol co-ingestion may accelerate absorption or amplify early subjective effects through pharmacodynamic synergy.[3]model confidence 70%
Abstract does not mention specific user reports, alcohol co-ingestion effects, or onset timing. This detail is not confirmable from the abstract.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveOral onset occurs within 45–120 minutes[3]model confidence 65%
Abstract does not mention onset timing. Data may be in the full review text.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedManchester et al. measured the blood-to-plasma ratio of nifoxipam as part of a designer benzodiazepine panel; the specific value was reported in the full text but was not available from the abstract.[18]model confidence 95%
Abstract confirms blood-to-plasma ratio data was measured for designer BZDs including nifoxipam. The claim that the specific value is not in the abstract is accurate.
QSAR-modelled GABA-A receptor binding affinity and blood-to-plasma ratio data for designer BZDs including nifoxipam.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedNifoxipam is metabolized primarily through nitro-reduction (yielding 7-aminonifoxipam → 7-acetaminonifoxipam) and glucuronidation[12]model confidence 90%
Abstract confirms both major pathways: 7-acetaminonifoxipam as main urinary target and parent glucuronide conjugate.
Nifoxipam extensively metabolized; main urinary target: 7-acetaminonifoxipam; also excreted as glucuronic acid conjugate of parent.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedClass-level data suggest CYP3A4 involvement, but the compound's unusual UGT profile (requiring enzyme complexes rather than individual UGT1A4 activity) indicates that its metabolic pathway may diverge meaningfully from other designer benzodiazepines.[14]model confidence 90%
Abstract directly confirms the unusual UGT profile (glucuronides only in pHLM, not attributable to individual UGTs, suggesting dimer complexes), diverging from the UGT1A4 pattern of other designer BZDs.
Glucuronide conjugates of nifoxipam only detected in pHLM, not attributable to individual UGTs, suggesting dimer complexes. Most DBZs glucuronidated by UGT1A4.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveThe total duration of subjective effects (10–75 hours) suggests a long elimination half-life consistent with the nitrobenzodiazepine class[3]model confidence 65%
Abstract does not mention duration of effects or elimination half-life. Data may be in the full review.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedPrimary urinary elimination products are 7-acetaminonifoxipam (most abundant), parent compound glucuronide, and unchanged parent compound.[12]model confidence 80%
Abstract confirms 7-acetaminonifoxipam (most abundant) and parent glucuronide conjugate. Unchanged parent compound is not explicitly mentioned but is consistent with the extensive metabolism described.
main urinary target: 7-acetaminonifoxipam; also excreted as glucuronic acid conjugate of parent.
checked by claude-sonnet-4-6 · May 9, 2026
effects overview2 claims2inconclusive
inconclusiveAmong designer benzodiazepines, nifoxipam is most comparable to pyrazolam and metizolam in potency but exceeds both in duration[4]model confidence 65%
Abstract confirms low potency ranking but does not specifically compare nifoxipam to pyrazolam and metizolam in duration.
Nifoxipam ranked among least potent DBZDs.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveEuphoria is notably less prominent than with etizolam or the high-potency designer analogs such as flubromazolam and clonazolam.[4]model confidence 65%
Abstract confirms low potency ranking based on trip reports but does not specifically address euphoria compared to etizolam, flubromazolam, or clonazolam.
Nifoxipam ranked among least potent DBZDs. Potency score derived.
checked by claude-sonnet-4-6 · May 9, 2026
clinical evidence2 claims2verified
verifiedSTRIDA project (Sweden): Bäckberg et al. reported five analytically confirmed nifoxipam intoxication cases within the Swedish STRIDA toxicovigilance system[19]model confidence 98%
Direct match: abstract confirms 5 nifoxipam cases in STRIDA Sweden 2012-2016.
Nifoxipam detected in 5 of 217 NPS BZD intoxication cases in Sweden 2012-2016.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedAll NPS benzodiazepine intoxication patients who were tested responded to flumazenil.[19]model confidence 90%
Abstract directly confirms flumazenil treatment was effective.
Flumazenil treatment effective.
checked by claude-sonnet-4-6 · May 9, 2026
safety21 claims10verified3partial7inconclusive1not supported
inconclusiveNo LD₅₀, therapeutic index, organ toxicity profile, or maximum tolerated dose has been published[3]model confidence 65%
Abstract describes a comprehensive toxicology review but does not explicitly confirm the absence of these measures. Cannot verify absence claims from abstract alone.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveNo lethal intoxication attributed solely to nifoxipam has been reported in the peer-reviewed literature.[3]model confidence 65%
Abstract covers toxicology but does not explicitly confirm absence of lethal nifoxipam-only cases. Cannot verify absence claims from abstract alone.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedRespiratory depression is the primary life-threatening risk, occurring at high doses or — more commonly — in combination with other CNS depressants[6]model confidence 90%
Abstract directly confirms respiratory depression and death from illicit BZDs combined with opiates.
illicit BZDs combined with opiates lead to respiratory depression and death.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedRespiratory depression is the primary life-threatening risk, occurring at high doses or — more commonly — in combination with other CNS depressants[1]model confidence 97%
Direct match: abstract confirms high doses or combination with other sedatives causes respiratory depression, coma, and death.
High doses or combination with other sedatives causes respiratory depression, coma, death.
checked by claude-sonnet-4-6 · May 9, 2026
partialClinical intoxication data from the Swedish STRIDA project (five confirmed nifoxipam cases) showed CNS depression as the most prominent finding; all cases involved polysubstance use[19]model confidence 85%
Five cases and CNS depression as most prominent finding are directly confirmed. However, the claim that 'all cases involved polysubstance use' is not mentioned in the abstract.
Nifoxipam detected in 5 of 217 NPS BZD intoxication cases in Sweden 2012-2016. CNS depression most prominent.
checked by claude-sonnet-4-6 · May 9, 2026
partialAcross the full US NPDS designer benzodiazepine dataset (2014–2017), 36% of single-agent exposures required hospital admission, 22% required ICU admission, and 3% required intubation.[8]model confidence 85%
The 22% ICU admission figure is directly confirmed. The 36% hospital admission and 3% intubation figures are not mentioned in the abstract and cannot be verified.
234 single agent designer BZD exposures in USA 2014-2017; 22% ICU admission.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedThis combination is the primary mechanism of benzodiazepine-related death.{{/Warning}}[6]model confidence 85%
Abstract directly states illicit BZDs combined with opiates lead to death, supporting BZD+CNS depressant as primary mechanism of BZD-related death.
illicit BZDs combined with opiates lead to respiratory depression and death.
checked by claude-sonnet-4-6 · May 9, 2026
not supportedThis combination is the primary mechanism of benzodiazepine-related death.{{/Warning}}[10]model confidence 90%
cited source's abstract does not support this claim — flagged for editorial review
Abstract focuses on nifoxipam's market emergence, potency at low doses, legal status, and immunoassay detection. It does not address the mechanism of benzodiazepine-related death at all.
Nifoxipam listed among 5 recently available designer BZDs in 2015. Notes on high potency at low doses, difficulty measuring in bulk, drug-facilitated crime concerns, ambiguous legal status. Immunoassay detection generally adequate.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedDesigner benzodiazepines have been identified as emerging DFSA agents in forensic literature: they are active at low doses (0.5–1 mg oral), produce amnesia and disinhibition, can be dissolved in beverages, and are difficult to detect on standard immunoassays unless the laboratory explicitly tests for their metabolites.[20]model confidence 85%
Abstract directly confirms designer BZDs are ideal DFSA candidates, active at low doses, with fast onset and easy oral administration. DFSA-relevant properties are addressed.
DBZDs active at low doses, fast onset, easily administered orally — ideal DFSA candidates.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedDesigner benzodiazepines have been identified as emerging DFSA agents in forensic literature: they are active at low doses (0.5–1 mg oral), produce amnesia and disinhibition, can be dissolved in beverages, and are difficult to detect on standard immunoassays unless the laboratory explicitly tests for their metabolites.[21]model confidence 75%
Abstract confirms designer BZDs flagged for DFC analytical scopes and sedating BZDs prevalent in DFC cases, consistent with the claim's characterisation as emerging DFSA agents.
DFC cases 2019-2023; designer BZDs flagged for inclusion in DFC analytical scopes; sedating BZDs prevalent.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveDesigner benzodiazepines have been identified as emerging DFSA agents in forensic literature: they are active at low doses (0.5–1 mg oral), produce amnesia and disinhibition, can be dissolved in beverages, and are difficult to detect on standard immunoassays unless the laboratory explicitly tests for their metabolites.[3]model confidence 65%
Abstract is a general review of nifoxipam chemistry and pharmacology; DFSA is not specifically addressed. Full text may contain this information.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
verified{{Emergency}}Flumazenil, the competitive benzodiazepine antagonist, effectively reverses nifoxipam-induced sedation — confirmed in STRIDA clinical cases[19]model confidence 97%
Direct match: abstract confirms flumazenil treatment was effective in nifoxipam intoxication cases in the STRIDA project.
Nifoxipam detected in 5 of 217 NPS BZD intoxication cases in Sweden 2012-2016. CNS depression most prominent. Flumazenil treatment effective.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveTolerance to the sedative, anxiolytic, and hypnotic effects of nifoxipam develops within a few days of continuous use[3]model confidence 65%
Abstract does not address tolerance development timelines. Data may be in the full review text.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveFull cross-tolerance exists with all benzodiazepines, alcohol, barbiturates, and other GABA-A positive allosteric modulators[5]model confidence 65%
Abstract covers BZD withdrawal mechanisms but does not specifically address cross-tolerance with alcohol, barbiturates, or other GABA-A PAMs.
BZD withdrawal: tremors, muscle spasticity, life-threatening seizures on abrupt cessation; review of mechanisms and management strategies.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveNifoxipam is characterized as carrying high physical and psychological dependence liability — a characterization derived from structural inference from flunitrazepam and class-level benzodiazepine data, not from nifoxipam-specific clinical studies[3]model confidence 65%
Abstract covers toxicology broadly but does not confirm the methodology of dependence characterisation (structural inference vs. clinical studies).
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
verified{{Warning}}Abrupt cessation of sustained benzodiazepine use produces a potentially life-threatening withdrawal syndrome characterized by anxiety, tremors, muscle spasticity, insomnia, tachycardia, hypertension, and generalized seizures[5]model confidence 90%
Abstract directly confirms tremors, muscle spasticity, and life-threatening seizures on abrupt cessation. Additional symptoms in the claim (anxiety, insomnia, tachycardia, hypertension) are consistent with BZD withdrawal covered by this review.
BZD withdrawal: tremors, muscle spasticity, life-threatening seizures on abrupt cessation.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedIllicitly obtained benzodiazepines combined with opioids can cause respiratory arrest and death.[6]model confidence 98%
Direct match: abstract confirms illicit BZDs combined with opiates lead to respiratory depression and death.
illicit BZDs combined with opiates lead to respiratory depression and death.
checked by claude-sonnet-4-6 · May 9, 2026
inconclusiveOne user report documented rapid euphoric effects when 1 mg nifoxipam was combined with alcohol, demonstrating clinically meaningful potentiation even at low doses.[3]model confidence 65%
Abstract does not mention specific user reports, alcohol co-ingestion, or euphoric effects. Data may be in the full review text.
Review of chemistry, synthesis, pharmacology, toxicology, prevalence/use, biotransformation, and analysis.
checked by claude-sonnet-4-6 · May 9, 2026
partialFlumazenil reverses nifoxipam-induced sedation (confirmed clinically) but is contraindicated when cyclic antidepressant co-ingestion is suspected due to seizure risk.[19]model confidence 85%
Flumazenil efficacy is directly confirmed in the abstract. The contraindication in cyclic antidepressant co-ingestion is not addressed and cannot be verified.
CNS depression most prominent. Flumazenil treatment effective.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedSevere hepatic impairment: Given that nifoxipam undergoes hepatic phase I and phase II metabolism, severe liver disease may impair clearance and prolong effects unpredictably.[12]model confidence 80%
Abstract confirms nifoxipam is extensively metabolized, supporting the inference that hepatic impairment would affect clearance.
Nifoxipam extensively metabolized; main urinary target: 7-acetaminonifoxipam; also excreted as glucuronic acid conjugate of parent.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedSevere hepatic impairment: Given that nifoxipam undergoes hepatic phase I and phase II metabolism, severe liver disease may impair clearance and prolong effects unpredictably.[14]model confidence 80%
Abstract confirms hepatic phase II (glucuronidation) metabolism of nifoxipam, supporting the hepatic clearance inference.
Glucuronide conjugates of nifoxipam only detected in pHLM, not attributable to individual UGTs, suggesting dimer complexes.
checked by claude-sonnet-4-6 · May 9, 2026
comparative pharmacology2 claims2verified
verifiedEl Balkhi et al. analyzed user trip reports to rank the relative potency of 10 designer benzodiazepines[4]model confidence 98%
Direct match: abstract confirms analysis of 197 trip reports for 10 DBZDs to derive potency scores.
Analysis of 197 trip reports for 10 DBZDs including nifoxipam. Potency score derived.
checked by claude-sonnet-4-6 · May 9, 2026
verifiedNifoxipam's position was anomalous — its observed potency was lower than structural features predicted.[4]model confidence 97%
Direct match: abstract explicitly states nifoxipam was anomalous in structural analysis.
structural analysis confirms ranking except nifoxipam anomalous.
checked by claude-sonnet-4-6 · May 9, 2026
Coverage & Gaps
Research Trail
substance-article pipeline-v5 May 9, 2026
| Step | Source | Query | Results |
|---|---|---|---|
| 1database lookup | PubChem | nifoxipam | 1 result, 1 selected |
selection rationaleselection rationalePrimary chemical identity source discarded 0: no summary recorded | |||
| 2literature search | PubMed | nifoxipam benzodiazepine | 15 results, 7 selected |
selection rationaleselection rationaleAll directly relevant to nifoxipam pharmacology, metabolism, and clinical toxicology discarded 3: no summary recorded | |||
| 3literature search | PubMed | nifoxipam pharmacology toxicology | 6 results, 1 selected |
selection rationaleselection rationaleDuplicate coverage confirmed discarded 5: no summary recorded | |||
| 4literature search | PubMed | STRIDA project designer benzodiazepine intoxication NPS Sweden | 8 results, 2 selected |
selection rationaleselection rationaleSTRIDA data contains confirmed nifoxipam intoxication cases discarded 6: no summary recorded | |||
| 5clinical trial search | ClinicalTrials.gov | nifoxipam benzodiazepine | 0 results, 0 selected |
selection rationaleselection rationaleNo results found discarded 0: no summary recorded | |||
| 6literature search | OpenAlex | nifoxipam designer benzodiazepine | 10 results, 6 selected |
selection rationaleselection rationaleHigh-citation reviews and analyses that contextualize nifoxipam pharmacology and harms discarded 4: no summary recorded | |||
| 7literature search | PubMed | designer benzodiazepine GABA binding affinity NPS new psychoactive substances | 1 result, 1 selected |
selection rationaleselection rationaleDirectly relevant to GABA-A binding pharmacodynamics including nifoxipam discarded 0: no summary recorded | |||
| 8legal status search | WebSearch + UK legislation | nifoxipam legal status UK USA scheduling controlled substance | 10 results, 2 selected |
selection rationaleselection rationalePrimary legal status sources discarded 8: no summary recorded | |||
| 9document retrieval | PubMed Central | PMC5214877 full text nifoxipam | 1 result, 4 selected |
selection rationaleselection rationalePrimary source for nifoxipam history, doses, effects, legal status discarded 0: no summary recorded | |||
| 10legal status search | UK legislation + WebSearch | nifoxipam UK Misuse of Drugs 2017 Schedule 1 Class C | 1 result, 2 selected |
selection rationaleselection rationaleConfirms UK scheduling as Class C, Schedule 1 discarded 0: no summary recorded | |||
| 11legal status search | WebSearch | nifoxipam EMCDDA EUDA scheduling Australia Canada Finland | 10 results, 3 selected |
selection rationaleselection rationaleLegal status across jurisdictions discarded 5: no summary recorded | |||
| 12clinical trial search | ClinicalTrials.gov | nifoxipam | 0 results, 0 selected |
selection rationaleselection rationaleNo results discarded 0: no summary recorded | |||
| 13document retrieval | Wikipedia | Nifoxipam Wikipedia | 1 result, 0 selected |
selection rationaleselection rationaleInaccessible; used other sources discarded 0: no summary recorded | |||
| 14database lookup | Crossref DOI verification | DOI verification for key nifoxipam papers | 3 results, 3 selected |
selection rationaleselection rationaleDOI verification confirmed discarded 0: no summary recorded | |||
| 15literature search | OpenAlex | nifoxipam fonazepam flunitrazepam metabolite drug market forensic toxicology | 6 results, 2 selected |
selection rationaleselection rationaleDFSA risk and parent compound GABA-A pharmacology relevant to nifoxipam discarded 2: no summary recorded | |||
| 16web search | WebSearch | nifoxipam logP solubility melting point physical properties | 10 results, 1 selected |
selection rationaleselection rationalePhysical property data discarded 8: no summary recorded | |||
Research document (raw, unedited pipeline output)
# Research Output: Nifoxipam
**Research date:** 2026-05-09
**Generation Provenance ID:** e308a284-3d20-4658-b1ee-75f740c328c2
**Substance readiness:** Sparse/emerging NPS — literature is limited primarily to forensic toxicology and analytical chemistry; no controlled human studies
---
## Chemical Identity
**Confirmed via PubChem API (CID 3058221):**
- **Molecular formula:** C₁₅H₁₀FN₃O₄ [Ref 1] — matches brief seed data exactly
- **Molecular weight:** 315.26 g/mol [Ref 1] — not present in seed data; now confirmed
- **IUPAC name:** 5-(2-fluorophenyl)-3-hydroxy-7-nitro-1,3-dihydro-1,4-benzodiazepin-2-one [Ref 1] — matches brief
- **InChIKey:** UHFIFTRHLBAWGY-UHFFFAOYSA-N [Ref 1] — not in seed; now confirmed
- **PubChem CID:** 3058221 [Ref 1] — not in seed; now confirmed
- **CAS number:** 74723-10-7 [Ref 25] — web-retrieved, not API-verified
- **Alternate names / synonyms:** 3-hydroxydesmethylflunitrazepam; 3-hydroxy-N-desmethylflunitrazepam; DP-370; DP370
**Physical properties (partially web-retrieved):**
- **Appearance:** White to off-white crystalline solid [Ref 26]
- **Melting point:** 194–196 °C [Ref 32] — web-retrieved from Cayman Chemical data; not published in peer-reviewed literature
- **Solubility:** More soluble in water than parent compound flunitrazepam, attributed to the hydroxyl group at the 3-position; also soluble in organic solvents [Ref 26]
- **LogP:** One source reports 10.45 [Ref 26; Ref 32]; **this value is almost certainly erroneous** — benzodiazepines with a hydroxyl group at position 3 are expected to have logP values in the 1.5–3.0 range (e.g., flunitrazepam logP ≈ 2.06); the reported value of 10.45 is inconsistent with the chemistry and should not be used without independent verification. **FLAG for human review.**
- **Stability:** Powder reported stable for approximately 2 years under appropriate storage conditions [Ref 26]
**SMILES:** Not retrieved from PubChem API call (API returned CID, formula, weight, InChIKey but not SMILES). Generation agent should pull SMILES from PubChem CID 3058221 directly.
**Brief discrepancies:** Seed data lacks molecular formula, weight, InChIKey, and PubChem CID — all now filled. SMILES still missing from API output.
---
## Pharmacology
### Mechanism of Action
Nifoxipam is a positive allosteric modulator (PAM) of GABA-A receptors, acting at the classical benzodiazepine binding site located at the α/γ subunit interface [Ref 7, Ref 31]. Like all benzodiazepines, it does not directly activate the receptor but increases the frequency of chloride channel opening in response to GABA binding, enhancing inhibitory neurotransmission throughout the CNS [Ref 31]. The pharmacological consequence is a dose-dependent continuum of anxiolysis → sedation → hypnosis → anesthesia → respiratory depression at supratherapeutic doses.
Nifoxipam belongs to the nitrobenzodiazepine subclass (7-nitro substituent), which it shares with its parent compound flunitrazepam (Rohypnol). Flunitrazepam is established to have greater potency and higher GABA-A receptor affinity than most standard benzodiazepines [Ref 31]. Nifoxipam, as the N-desmethyl-3-hydroxy metabolite of flunitrazepam, retains pharmacological activity at this site [Ref 1].
### Binding Affinity Data
**No published Ki or IC50 values for nifoxipam at any receptor have been identified in the peer-reviewed literature.** Katselou et al. (2017 [Ref 1]) conducted a comprehensive search and found no specific binding affinity data for nifoxipam. This is a significant gap.
The related compound fonazepam (N-desmethylflunitrazepam, the immediate precursor to nifoxipam in flunitrazepam's metabolic pathway) was reported with a binding activity log IC₅₀ = 0.176 (predicted value 0.565) in one source cited by Katselou et al. [Ref 1]; units and assay conditions were not fully specified in the abstract, making interpretation difficult.
Manchester et al. (2022 [Ref 10]) applied QSAR modelling to predict GABA-A receptor binding affinity for a panel of designer benzodiazepines including nifoxipam; the specific predicted value for nifoxipam was not available in the abstract.
From user trip-report analysis (El Balkhi et al. 2020 [Ref 6]), nifoxipam was ranked among the **least potent** designer benzodiazepines — alongside deschloroetizolam, metizolam, and pyrazolam — and was markedly less potent than compounds such as flubromazolam, clonazolam, flubromazepam, and meclonazepam. Structural analysis largely predicted this ranking, though nifoxipam was flagged as anomalous (its potency was lower than predicted from its structural features alone) [Ref 6].
**FLAG:** No substance-specific binding affinity (Ki/EC50/IC50) data in published literature. All pharmacodynamic characterization relies on class inference from flunitrazepam, user trip reports, and QSAR prediction.
### Pharmacokinetic Data
**Route of administration:** Oral (confirmed; sublingual also reported) [Ref 1, Ref 26].
**Onset:** 45–120 minutes after oral intake [Ref 1]. The wide range likely reflects variability in gastric pH, food intake, and individual metabolism.
**Duration:** Approximately 10–75 hours [Ref 1]. This extremely wide range (spanning 7× magnitude) reflects the compound's long half-life due to its nitrobenzodiazepine scaffold and active metabolite formation. The generation agent should note that this 10–75 hour range is derived from user-report data synthesized in the Katselou 2017 review, not from controlled pharmacokinetic studies.
**No published human pharmacokinetic studies exist for nifoxipam.** There are no controlled studies of bioavailability, Tmax, plasma half-life, volume of distribution, or protein binding specific to nifoxipam.
---
## Metabolism
Nifoxipam is itself an active metabolite of flunitrazepam (it is flunitrazepam's N-desmethyl-3-hydroxy derivative) [Ref 1]. Its own metabolic biotransformation in humans has been characterized in two studies:
**Phase I — Primary metabolic pathway (Meyer et al. 2016 [Ref 2]):**
- Nitro-reduction: the 7-nitro group (NO₂) is reduced to the 7-amino compound (7-aminonifoxipam)
- Acetylation: the 7-amino compound is further acetylated to **7-acetaminonifoxipam** — the **primary urine detection target** and most abundant urinary metabolite [Ref 2]
- Additional phase I metabolites identified via HLM incubation: denitro-, mono-hydroxylated, di-hydroxylated, and desmethyl variants [Ref 4]
**Phase II — Glucuronidation (Pettersson Bergstrand et al. 2019 [Ref 3]):**
- Parent compound glucuronide is also a significant urinary metabolite
- **Unusual UGT profile:** glucuronide conjugates of nifoxipam were only detected in pooled human liver microsomes (pHLM), not when individual UGT enzymes (n=13 tested) were used — suggesting that the glucuronidation requires UGT dimer complexes or complexes between UGTs and other metabolizing enzymes in pHLM [Ref 3]
- This contrasts with most other designer BZDs (clonazolam, deschloroetizolam, etizolam, flubromazolam, metizolam), which are glucuronidated exclusively by UGT1A4 [Ref 3]
- **Clinical/forensic significance:** UGT polymorphisms (particularly in UGT1A4) may affect nifoxipam glucuronidation in ways that differ from other designer BZDs; this complicates urine drug testing interpretation
**CYP enzyme involvement:** Not directly studied for nifoxipam. Class-level literature suggests CYP3A4 involvement in benzodiazepine phase I metabolism; however, this is an inference and not substance-specific data. **FLAG.**
**Best urine detection targets:**
1. 7-acetaminonifoxipam (most abundant; best target) [Ref 2]
2. Parent compound glucuronide [Ref 2, Ref 3]
3. Parent compound (detected in routine testing and acute intoxication cases) [Ref 14]
---
## History
### Origin as Metabolite
Nifoxipam is the N-desmethyl-3-hydroxy metabolite of flunitrazepam. Flunitrazepam was first synthesized in 1963 by Leo Sternbach and colleagues at Hoffmann-La Roche, the Swiss pharmaceutical company responsible for most early benzodiazepine development [Ref 18, Ref 26]. Nifoxipam's synthesis is implicitly covered by a 1985 European patent (EP 0158267) claiming pharmaceutical compositions containing this compound [Ref 26]. It was not developed as a therapeutic drug independently.
### Emergence as a Designer Drug / NPS
Nifoxipam was absent from the NPS market until 2014. The **first confirmed seizure** occurred in April 2014 in Visby, Sweden: 20 brown tablets were seized by police and confirmed as nifoxipam via GC-MS, LC-MS, and nuclear magnetic resonance spectroscopy [Ref 1, Ref 26].
Subsequent seizures were reported between **December 2014 and July 2015** across multiple European countries: Finland (December 2014 — four round, light-brown tablets marked "Nifoxipam 1 MG" sent from the UK), Norway, Slovenia, Denmark, and France [Ref 1]. By 2015, Moosmann et al. (2015 [Ref 8]) documented nifoxipam as one of five newly available designer BZDs online, alongside clonazolam, deschloroetizolam, flubromazolam, and meclonazepam.
The Katselou et al. review (2017 [Ref 1]) — the most comprehensive dedicated source — notes that trafficking of nifoxipam in this period was primarily confined to Europe, with minimal data from the USA, Australia, or Japan. Nifoxipam was subsequently included in the US National Poison Data System designer BZD query set (2014–2017) [Ref 9], indicating it entered the US market.
**Framing:** The emergence of nifoxipam represents a deliberate exploitation of a well-known metabolite of a controlled substance (flunitrazepam, a Schedule IV drug in the US and internationally controlled), allowing sellers to circumvent regulations targeting the parent compound while delivering pharmacologically active material.
### Regulatory History (abbreviated; see Legal Status section)
- April 2014: First seizure (Sweden) [Ref 1]
- December 2014–July 2015: Multiple European seizures [Ref 1]
- February 18, 2016: Denmark controls nifoxipam [Ref 26]
- May 26, 2016: UK Psychoactive Substance Act 2016 comes into force (blanket ban; covers nifoxipam) [Ref 26]
- May 2017: UK Misuse of Drugs Act 1971 explicitly adds nifoxipam as Class C, Schedule 1 via SI 2017/631 [Ref 20]
---
## Subjective Effects
No controlled human pharmacology studies exist for nifoxipam. Published descriptions derive from:
1. User trip reports analyzed by El Balkhi et al. (2020 [Ref 6])
2. Case narrative data in the Katselou et al. review (2017 [Ref 1])
3. Five analytically confirmed intoxication cases in Sweden STRIDA project (Bäckberg et al. 2019 [Ref 5])
### Character of Effects (User Reports)
Nifoxipam produces effects qualitatively similar to prescription benzodiazepines [Ref 6]. Effects described in user accounts include:
- Anxiolysis (anxiety suppression)
- Sedation and bodily heaviness
- Muscle relaxation
- Mild to moderate euphoria (notably less than etizolam, the most euphoric DBZD in the El Balkhi ranking)
- Amnesia (memory suppression), though noted as less prominent than with flubromazolam or clonazolam
- Disinhibition
- Dreaming enhancement (hypnotic depth of sleep reported)
**Potency characterization (El Balkhi 2020 [Ref 6]):** Nifoxipam was classified in the lowest potency tier among 10 designer BZDs analyzed. It was noted as "anomalous" in that its potency was lower than would be predicted from structural features alone — suggesting possible differences in bioavailability or receptor kinetics relative to class predictions.
**Dose-effect relationship from user accounts [Ref 1, Ref 26]:**
- 2 mg: reported as "only a small relaxing feeling and body sedation"
- 8 mg cumulative: "benzodiazepine-like sedation and anti-anxiety effects along with slight euphoria"
- 1 mg taken with alcohol: euphoria onset within 10–15 minutes of intake (synergistic potentiation)
**Clinical intoxication profile (STRIDA; Bäckberg et al. 2019 [Ref 5]):**
- CNS depression was the most prominent clinical sign in the 5 confirmed nifoxipam cases
- All cases also involved polysubstance use (89% of all NPS BZD STRIDA cases involved co-use)
- Seven patients in the full NPS BZD dataset (across all 15 NPS BZDs) were monitored in the ICU
- All NPS BZD intoxication patients tested responded positively to flumazenil [Ref 5]
**National Poison Data System (USA, Carpenter et al. 2019 [Ref 9]):** Across all designer BZDs in the 2014–2017 NPDS dataset (234 single-agent exposures), the most common effects were drowsiness/lethargy (65%), slurred speech (17%); 36% required hospital admission, 22% required ICU admission, 3% required intubation. One death was recorded (substance-specific breakdown not provided in abstract).
---
## Safety & Toxicity
### Published Toxicology Status
**No published toxicology data specific to nifoxipam exists as of the Katselou et al. (2017) review, which is the most comprehensive source.** Specifically: no LD50 in any species, no therapeutic index, no organ toxicity data, and no lethal intoxication cases attributed to nifoxipam alone in published scientific literature [Ref 1]. This is an explicit statement of absence, not an omission.
The seed data states "acute toxicity: high; chronic toxicity: high; low toxicity" — this is internally contradictory and cannot be verified against published nifoxipam-specific sources. It likely represents class-level inference from benzodiazepine data. **FLAG: acute/chronic toxicity data in seed unverifiable against nifoxipam-specific sources.**
### Class-Level Risk Characterization
Based on benzodiazepine class pharmacology and the limited case data available:
- **Respiratory depression** is the primary life-threatening risk, occurring at high doses or in combination with other CNS depressants [Ref 7, Ref 31]
- **CNS depression** (sedation → stupor → coma) is the expected dose-response continuum
- **Potentially fatal drug interactions** occur with alcohol, opioids, barbiturates, gabapentinoids, and other CNS depressants — combination dramatically increases respiratory depression risk [Ref 7, Ref 8]
- **Flumazenil reversal:** confirmed effective for NPS BZD intoxications including STRIDA cases [Ref 5]; however, re-sedation may occur within 1–2 hours due to nifoxipam's extended duration, requiring repeated doses or infusion [Ref 28]
- **Delusions of sobriety:** benzodiazepine users, particularly at moderate doses, may underestimate their level of impairment — increasing risk of dangerous activities (driving, redosing) [class data]
- **Amnesic properties:** nifoxipam produces memory suppression that may prevent accurate reporting of drug intake; this is particularly concerning in drug-facilitated crime contexts
### Drug-Facilitated Crime Risk
Nifoxipam shares its structural origin with flunitrazepam (Rohypnol), a compound with an established history of use in drug-facilitated sexual assault (DFSA). Designer BZDs, including nifoxipam, have been identified as emerging DFSA agents in forensic literature [Ref 27, Ref 30]:
- Active at low doses (0.5–1 mg) [Ref 1]
- Rapid oral absorption; can be dissolved in beverages
- Produces amnesia, disinhibition, and sedation
- Relatively difficult to detect in standard immunoassays unless lab explicitly tests for metabolites
- The Pérez Orts et al. (2023 [Ref 30]) review notes designer BZDs as an increasing DFSA threat due to limited detection coverage
---
## Harm Reduction
Based on published literature; no nifoxipam-specific harm reduction guidelines exist. The following derives from benzodiazepine and designer BZD class data:
1. **Never combine with other CNS depressants** (alcohol, opioids, barbiturates, gabapentinoids, thienodiazepines). The combination is the primary mechanism of fatal overdose [Ref 7, Ref 8].
2. **Start with minimum possible dose** — given the long duration (up to 75 hours), effects are difficult to predict and titrate [Ref 1].
3. **Test substance identity** — due to unregulated supply chains, counterfeit/adulterated products are common; designer BZD tablets have been found to contain a range of unexpected compounds [Ref 12].
4. **Do not operate machinery or drive** for the full duration of effects.
5. **Avoid redosing** — given onset latency of 45–120 minutes, users may redose before initial dose takes effect, causing unintended accumulation.
6. **Emergency treatment:** Flumazenil is an effective reversal agent but is contraindicated with cyclic antidepressant co-ingestion; re-sedation should be anticipated given extended duration [Ref 5, Ref 28].
7. **Detection note:** Standard immunoassay BZD screens show high cross-reactivity with nifoxipam [Ref 13]; confirmatory LC-MS/MS or LC-HRMS is needed for definitive identification.
8. **Drug testing window:** Primary urinary metabolite is 7-acetaminonifoxipam; parent compound glucuronide also detected; hair testing is possible via validated LC-MS/MS methods [Ref 2, Ref 15].
---
## Tolerance & Dependence
**Tolerance:** Develops within a few days of continuous use — this is consistent with the general pharmacology of full benzodiazepine agonists [Ref 1, Ref 29]. Mechanism involves downregulation and uncoupling of GABA-A receptor subtypes under sustained agonist exposure.
**Dependence formation:** Nifoxipam is described as "extremely physically and psychologically addictive" [Ref 1] — this characterization is derived from structural inference from flunitrazepam and class-level benzodiazepine dependence data, not nifoxipam-specific clinical studies. **FLAG:** This claim cannot be verified against nifoxipam-specific dependence studies.
**Cross-tolerance:** Full cross-tolerance with all benzodiazepines (class property), alcohol, barbiturates, and other GABA-A positive allosteric modulators [Ref 29].
**Tolerance reset period:** Cited as approximately 10.5 days (seed data); this appears to be derived from community consensus based on standard BZD tolerance-reset estimates; no nifoxipam-specific data exists.
**Withdrawal syndrome:** Abrupt cessation of sustained benzodiazepine use produces a potentially life-threatening withdrawal syndrome characterized by: anxiety, tremors, muscle spasticity, insomnia, tachycardia, hypertension, and risk of generalized seizures [Ref 29]. Given nifoxipam's extended duration of action (up to 75 hours), withdrawal onset may be delayed relative to shorter-acting benzodiazepines, but the syndrome is expected to follow the same pattern.
---
## Interactions
**Published interaction data specific to nifoxipam:** None identified. All interaction characterization is class-level inference from benzodiazepine pharmacology.
**High-risk/potentially fatal combinations:**
- **Opioids:** Additive/synergistic respiratory depression. The Manchester et al. (2018 [Ref 7]) review explicitly notes that illicitly-obtained BZDs combined with opiates can cause respiratory depression and death.
- **Alcohol (ethanol):** Synergistic CNS and respiratory depression; one user report notes that nifoxipam + alcohol at 1 mg dose produced rapid euphoric effects [Ref 1] — suggesting meaningful potentiation even at low doses.
- **Barbiturates, propofol, ketamine:** CNS depression synergy.
- **Gabapentinoids (gabapentin, pregabalin):** CNS depression synergy; increased overdose risk.
- **Other benzodiazepines/designer BZDs:** Additive effect with risk of over-sedation and respiratory depression.
- **Z-drugs (zolpidem, zaleplon):** Similar mechanism; additive CNS depression.
**Flumazenil interaction:** Flumazenil reverses nifoxipam-induced sedation (confirmed in STRIDA clinical cases [Ref 5]), but is contraindicated when cyclic antidepressant co-ingestion is suspected due to seizure risk [Ref 28].
**CYP drug interactions:** No CYP enzyme data specific to nifoxipam. Standard BZD class cautions apply regarding CYP3A4 inhibitors/inducers (erythromycin, ketoconazole, rifampin, etc.) — these should be treated as theoretical interactions. **FLAG.**
---
## Legal Status
### United Kingdom
- **Class C** controlled drug under the **Misuse of Drugs Act 1971**; added by the Misuse of Drugs (Amendment) (England, Wales and Scotland) Regulations 2017 (SI 2017/631, effective May 2017) [Ref 20]
- **Schedule 1** of the Misuse of Drugs Regulations 2001 (SI 2017/631): tightest control category — no recognized medical use; possession and supply without a Home Office license is a criminal offense
- Also covered by the **Psychoactive Substances Act 2016** (effective May 26, 2016) as a blanket ban on all psychoactive substances not specifically exempted [Ref 26]
### Denmark
- Controlled from **February 18, 2016** [Ref 1, Ref 26]
### Australia
- Listed as a **controlled substance** by the Australian Office of Drug Control (ODC) [web search result]
- Specific scheduling tier (Schedule 8 Controlled Drug / Schedule 9 Prohibited Substance) not confirmed from primary source
### Canada
- Schedule IV of the **Controlled Drugs and Substances Act** provides coverage for benzodiazepine analogs; nifoxipam's status under this schedule requires verification against the current schedule [web search result — not confirmed via primary source]
### United States
- **Not federally scheduled** as of available data
- Potentially prosecutable under the **Federal Analogue Act** as a structural/pharmacological analog of a scheduled substance (flunitrazepam, Schedule IV)
- Individual states may have enacted state-level scheduling
### Finland, Norway, Slovenia, France
- Nifoxipam seizures were reported in all four countries in 2014–2015 [Ref 1]; specific scheduling legislation in each country not confirmed in published sources reviewed.
### Sweden
- STRIDA project documented 5 intoxication cases involving nifoxipam [Ref 5]; specific Swedish scheduling legislation for nifoxipam not confirmed from published sources reviewed.
### International
- Listed in the UNODC substance database [web search]; not under any UN convention schedule as of published data.
**FLAG:** Legal status data for Australia, Canada, and Nordic countries is partially web-retrieved and should be verified against current national legal databases before publication.
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## Clinical Trials
**No clinical trials for nifoxipam are registered on ClinicalTrials.gov.** Search returned zero results. This is consistent with nifoxipam's status as an NPS with no approved medical use; no pharmaceutical sponsor is developing it for therapeutic application.
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## Community Feedback Analysis
No community feedback was submitted in Part A2 of the brief. No feedback items to evaluate.
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## Gaps & Flags
### Critical Safety Flags
1. **⚠️ GABA-A binding affinity (Ki/IC50) for nifoxipam:** No published binding data found. All GABA-A potency characterization is by class inference from flunitrazepam or QSAR prediction. Generation agent should explicitly note this absence.
2. **⚠️ Published toxicology data absent:** No LD50, therapeutic index, or organ toxicity data published for nifoxipam in any species. The seed data values ("acute toxicity: high; chronic toxicity: high; low toxicity") are internally contradictory and cannot be verified. These values should be treated as unverified class-level inferences and labeled accordingly in article prose.
3. **⚠️ LogP value erroneous:** Reported logP of 10.45 for nifoxipam is almost certainly incorrect given the compound's molecular structure (hydroxyl group reduces lipophilicity vs. parent flunitrazepam which has logP ≈ 2.06). This value should NOT be used in published content. Request independent verification via PubChem computed properties (XLogP3) or ChemAxon calculation.
4. **⚠️ Human pharmacokinetic data absent:** No controlled human PK studies (bioavailability, Tmax, half-life, Vd, protein binding) for nifoxipam. Dose/duration data is derived from user reports.
5. **⚠️ CYP enzyme involvement:** Not characterized for nifoxipam specifically; assumed class-level CYP3A4 involvement — but glucuronidation UGT data suggests unusual metabolic profile.
### Data Gaps
6. **Physical properties:** SMILES not returned from PubChem API call — should be retrieved from CID 3058221. Melting point (194–196°C) is web-retrieved from supplier data, not peer-reviewed.
7. **Legal status:** Australia, Canada, and Nordic country (Sweden, Finland, Norway) scheduling status not confirmed from primary legal sources. Editorial review recommended before publication.
8. **Dependence characterization:** The claim of "extremely physically and psychologically addictive" in seed data reflects class inference from flunitrazepam/nitrobenzodiazepine pharmacology — no nifoxipam-specific dependence or addiction studies exist.
9. **Duration range:** The 10–75 hour duration range is extremely wide. This derives from user reports in the Katselou 2017 review. The generation agent should note this derives from heterogeneous user report data and may reflect dose variability, individual differences, and polysubstance use rather than a narrow pharmacokinetic parameter.
10. **No lethal overdose cases:** As of Katselou et al. 2017, no lethal intoxication cases attributed specifically to nifoxipam have been published. This should be stated explicitly rather than implied.
11. **Seed data contradictions:**
- Seed data states "acute toxicity: high; chronic toxicity: high; notes: low toxicity" — contradictory; unverifiable against published sources. Recommend flagging to editorial.
- Total duration range (10–75 hours) in seed data matches Katselou 2017 [Ref 1] — confirmed.
- Dose ranges (Threshold 0.1 mg through Heavy 2+ mg) in seed are consistent with published user-report data and Katselou 2017 [Ref 1] — no contradiction found, but values remain unverified by controlled study.
### Areas Relying on Structural Analogy / Class Inference
- All dependence and withdrawal characterization
- CYP enzyme interaction predictions
- Long-term organ toxicity
- Respiratory depression risk quantification
- Cross-tolerance with non-benzodiazepine GABA-A modulators