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psx:substance/methaqualone/value/timeline/smoked/onset@1

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Closure of psx:substance/methaqualone/value/timeline/smoked/onset@1: 1 upstream, 0 downstream.

psx:substance/methaqualone/value/timeline/smoked/onset@1
└─ derived_from  proposal/timeline/a7516d79-e5e7-4f13-bd20-5d4709adbfe3  timeline · smoked · onset

indented by distance from this node, not by parentage

1Provenance card

the boundary, as counts

Sources

459 with DOI

1 strong · 35 moderate · 9 weak

Compilations

12026-05-12T03:55:12.378Z

pipeline-v5 · prompt hash not recorded — run predates 2026-09

Decisions

39last ruled 2026-06-04

0 awaiting a ruling

Issued documents

42026-10-19T20:32:52.274Z

notice · info card · emergency

Searches

221 with no results

queries and counts on the build

Claims checked

9872 supported

72 supported · 26 not

Correspondence

0received

consent field ships in Phase 4

Edges

315

derivations recorded for this entity

Complete over 45 sources, 1 compilation, and 39 decisions.Not here: the private journal (never).Working material — drafts, discards, unsupported claims — is listed below and readable on the working page.Cite: psychedex.org/substances/methaqualone/archive

2Build

one panel per compilation run

generation run 2026-05-12

76 min completedmodel pipeline-v5plan not recordedrun/60a3de8c…

Selection

results seen122
selected by the model53
consumed as sources45

Verification

claims checked98
supported53
partially supported19
not supported1
inconclusive25
  • record
  • seen / partial
  • working

The model's own caveats

  • sparse_evidence
  • safety_note

Reproduce

inputs
45 source keys (listed under Sources)
plan
not recorded — template version, prompt hash and git SHA are written from 2026-09 onward
model
pipeline-v5
streams
none — agent transcripts are persisted from 2026-09 onward
22 searches — query, source, results, what was kept and why
22 searches for this run
#sourcequeryseenkeptrationale
1PubMedmethaqualone South Africa Mandrax abuse prevalence1010Epidemiological data on methaqualone abuse in South Africa, which is the main remaining active market
2PubMedmethaqualone pharmacokinetics metabolism half-life65Human pharmacokinetic and metabolism data
3PubMedmethaqualone drug interactions alcohol CNS depressants combination64Drug interaction data between methaqualone and alcohol/other depressants
4PubChemmethaqualone11Primary chemical identity verification
5OpenAlexmethaqualone Quaalude abuse recreational drug 1970s history41SL-164 analog case report relevant for new designer drug context
6OpenAlexmethaqualone quinazolinone sedative hypnotic103Selected papers directly relevant to methaqualone pharmacology
7PubMedmethaqualone metabolism cytochrome P450 CYP liver11Key CYP enzyme data for methaqualone metabolism
8ClinicalTrials.gov · absencemethaqualone00No relevant trials - methaqualone is Schedule I in US, no current clinical development
9PubMedmethaqualone pharmacology GABA receptor mechanism66All directly relevant to methaqualone pharmacology
10PubMedPMID 1016511Human pharmacokinetic parameters
11WebSearchmethaqualone half-life plasma protein binding volume distribution pharmacokinetics102PK parameters synthesis
12PubMedmethaqualone urinary metabolites 4-hydroxymethaqualone32Metabolite characterization
13PubMedmethaqualone plasma levels oral absorption Morris 197211Original PK absorption paper
14PubChem REST APICID 6292 properties13Chemical identity verification
15WebSearchmethaqualone Quaalude brand names Lemmon Company commercial history102Commercial/brand history
16WebSearchmethaqualone Kacker Zaheer 1951 synthesis discovery India102Discovery history
17Erowid Timeline—11Historical chronology
18WebSearchmethaqualone Schedule I DEA scheduling history 1973102Legal scheduling history
19WebSearchmethaqualone legal status UK Canada Australia EU scheduling102International legal status
20PubMedPMID 613007611Human abuse liability data
21WebSearchmethaqualone physical properties melting point solubility101Physical property verification
22WebSearchmethaqualone smoked white pipe South Africa pharmacokinetics102Smoked ROA characterization
98 claims by section — every cited sentence, checked against its source
safety32 · 23 ok
  • The only published LD50 for methaqualone is 240 mg/kg (intraperitoneal, mouse)supported

    Mouse LD50 for methaqualone 240 mg/kg. pmid:493294

  • Doses exceeding 300 mg oral may produce dangerous effects in individuals without tolerance, though this threshold lacks formal determination in dose-escalation studiessupported

    Methaqualone 300 mg caused elevated scores on euphoria, physical sedation, and abuse liability scales in 24 recreational sedative users vs placebo. pmid:6130076

  • Claim in safety — inconclusiveinconclusiveworking →

  • All GABAA-active agents — benzodiazepines, barbiturates, GHB, neurosteroids, anesthetic agents — carry additive or synergistic risk of respiratory depression in combination with methaqualonesupported

    Review of GABAergic sedative-hypnotics including methaqualone; covers abuse potential, respiratory depression risk, withdrawal syndromes. jcph.1922

  • In a series of 349 acute poisoning cases involving non-barbiturate hypnotics, Ruedy (1973) found unconsciousness and respiratory depression as the most common features, with 6 deaths and 5 surviving patients remaining unconscious for more than 24 hours.partially supported

    Prospective study of 349 poisoning patients; non-barbiturate hypnotics most frequent; unconsciousness, respiratory depression, metabolic acidosis most common findings. 6 deaths. pmid:4742490

  • Claim in safety — inconclusiveinconclusiveworking →

  • Dose-dependent respiratory depression is the primary life-threatening effect, shared with all GABAA positive allosteric modulatorssupported

    Review of GABAergic sedative-hypnotics including methaqualone; covers abuse potential, respiratory depression risk, withdrawal syndromes. jcph.1922

  • No antidote is established for clinical use; naloxone (10 mg/kg in mice) partially antagonized methaqualone lethality, but the mechanism remains unclear and naloxone is not a standard treatment for methaqualone overdose in humans.supported

    Mouse LD50 for methaqualone 240 mg/kg; naloxone increased LD50 to 416 mg/kg. pmid:493294

  • Haider and Oswald (1970) described a late withdrawal syndrome occurring 1–3 weeks after methaqualone overdose: insomnia, restlessness, elevated REM sleep, epileptic phenomena, and deliriumsupported

    Withdrawal syndrome can occur up to 1-3 weeks post-overdose with insomnia, restlessness, raised REM sleep, epileptic phenomena, delirium. pmid:4317051

  • Claim in safety — inconclusiveinconclusiveworking →

  • Claim in safety — inconclusiveinconclusiveworking →

  • In the South African context, methaqualone (Mandrax) use is epidemiologically associated with sexual risk-taking, reduced ability to negotiate safer sex, increased HIV transmission risk, and drug-facilitated sexual assault.partially supported

    Methaqualone identified as substance used in drug-facilitated sexual assault. Toxicological screening not routinely available in clinical forensic practice in Western Cape. j.forsciint.2018.04.028

  • The compound's documented high abuse liability and compulsive redosing urge contribute to a pattern of escalating use. Euphoria reinforces repeated administration, while amnesia may mask the extent of impairment from the user's perspective.partially supported

    Methaqualone 300 mg caused elevated scores on euphoria, physical sedation, and abuse liability scales in 24 recreational sedative users vs placebo. pmid:6130076

  • Pharmacodynamic tolerance: GABAA receptor adaptation at the cellular level. In mice, continuous methaqualone exposure produces measurable tolerance (significantly reduced sleep-times) within 36 days.supported

    Tolerance and physical dependence produced in mice after 36 days exposure via food pellets. Tolerance shown by reduced sleep-times. pmid:1239784

  • Pharmacokinetic tolerance: CYP3A4 enzyme induction increases the rate of methaqualone metabolism. In clinically dependent Mandrax patients, hepatic drug-metabolizing capacity was the highest measured for any drug-exposed group — manifested as the shortest antipyrine half-life reported in the literature for drug-exposed individuals.partially supported

    3 Mandrax-dependent patients studied; very high drug-metabolizing capacity on admission; marked drug tolerance. Induction of drug-metabolizing capacity contributed to tolerance. pmid:5085238

  • Physical dependence has been confirmed in mice, rats, and humanspartially supported

    Tolerance and physical dependence produced in mice after 36 days exposure via food pellets. pmid:1239784

  • Claim in safety — inconclusiveinconclusiveworking →

  • Physical dependence has been confirmed in mice, rats, and humanssupported

    3 Mandrax-dependent patients studied; very high drug-metabolizing capacity on admission; marked drug tolerance. pmid:5085238

  • Epileptic phenomena and delirium — documented 1–3 weeks post-exposuresupported

    Withdrawal syndrome can occur up to 1-3 weeks post-overdose with insomnia, restlessness, raised REM sleep, epileptic phenomena, delirium. pmid:4317051

  • Cross-tolerance with barbiturates has been demonstrated: Mandrax-dependent animals show reduced sensitivity to pentobarbital-induced sleepsupported

    Animals withdrawn from chronic Mandrax (methaqualone:diphenhydramine 10:1) showed significant cross-tolerance to intracerebroventricularly administered pentobarbital. pmid:4155651

  • Cole et al. (1982) demonstrated significantly elevated euphoria and abuse-liability scores compared to placebo in recreational sedative users, with a euphoriant profile exceeding that of diazepam at tested doses.supported

    Methaqualone 300 mg caused elevated scores on euphoria, physical sedation, and abuse liability scales in 24 recreational sedative users vs placebo. Diazepam 20 mg showed some euphoriant effect. pmid:6130076

  • The interaction operates through pharmacodynamic sensitization: ethanol reduces the minimum effective dose of methaqualone at the target organ level, independent of any pharmacokinetic alteration of methaqualone distribution or eliminationsupported

    Ethanol increases duration of methaqualone hypnosis via pharmacodynamic sensitization (reduced minimum effective dose) not altered PK. Methaqualone distribution and elimination unaffected by ethanol. pmid:644120

  • Claim in safety — inconclusiveinconclusiveworking →

  • {{Warning}}The alcohol-methaqualone interaction persists for at least 3 days after a single therapeutic dose of methaqualonesupported

    Alcohol interaction with Mandrax apparent in Stroop test and visual analogue scale up to 3 days post-dose. pmid:892953

  • In mouse models, methaqualone (50 mg/kg) prolonged ethanol-induced narcosis by 269%supported

    Methaqualone (50 mg/kg) prolonged ethanol-induced narcosis by 269%. pmid:493294

  • The in vitro mechanism involves synergistic inhibition of brain Na-K-ATPase, with greatest inhibition at low K+ and high Na+ ratios.supported

    Combined methaqualone + ethanol inhibits brain Na-K-ATPase in mixed/non-competitive manner, with greatest effect at low K+/high Na+ ratios. pmid:6260047

  • Claim in safety — inconclusiveinconclusiveworking →

  • Claim in safety — inconclusiveinconclusiveworking →

  • Concurrent use of other CNS depressants (alcohol, benzodiazepines, barbiturates, opioids, GHB, baclofen): Synergistic respiratory depression risk renders any combination potentially lethal.supported

    Review of GABAergic sedative-hypnotics including methaqualone; covers abuse potential, respiratory depression risk, withdrawal syndromes. jcph.1922

  • Claim in safety — inconclusiveinconclusiveworking →

  • Pregnancy: Methaqualone crosses the placental barrier; pharmacokinetics are altered during pregnancy and labour.partially supported

    Methaqualone half-life prolonged during labour; diminished in pregnancy compared to non-pregnant controls. pmid:6933942

  • History of substance use disorders: High abuse liability and compulsive redosing potential make methaqualone contraindicated in individuals with vulnerability to substance dependence.supported

    Methaqualone 300 mg caused elevated scores on euphoria, physical sedation, and abuse liability scales in 24 recreational sedative users vs placebo. pmid:6130076

pharmacology16 · 13 ok
  • Methaqualone acts as a positive allosteric modulator (PAM) of GABAA receptors — the principal inhibitory ligand-gated ion channels in the central nervous systemsupported

    Methaqualone is a PAM at alpha1,2,3,5 beta2,3 gamma2S GABAA receptors. mol.115.099291

  • Unlike benzodiazepines, barbiturates, or neurosteroids, methaqualone binds at the transmembrane β(+)/α(−) subunit interface, the same site occupied by the general anesthetic etomidatesupported

    Acts through transmembrane beta+/alpha- subunit interface overlapping with etomidate site. mol.115.099291

  • This binding site was definitively localized in 2024 through cryo-electron microscopy at atomic resolution, which demonstrated that methaqualone and its more potent derivative PPTQ insert more deeply into the intersubunit interface than either propofol or etomidate, widening the extracellular half of the ion-conducting pore and destabilizing the hydrophobic activation gate.supported

    Cryo-EM study localizing methaqualone and PPTQ binding sites at GABAA receptor transmembrane intersubunit interfaces targeted by propofol and etomidate. Binding results in widening of ion-conducting pore, destabilizing hydrophobic activation gate. s41467-024-49471-y

  • Methaqualone displays negligible activity at a broad panel of non-GABAA CNS targets, including other neurotransmitter receptors and transporterssupported

    Negligible activity at other CNS targets. mol.115.099291

  • In vivo, the compound selectively antagonizes GABA-deficiency-induced convulsions (isoniazid model) in mice but does not block strychnine-induced convulsions (a glycine-receptor model), confirming GABAergic rather than glycinergic specificitysupported

    Methaqualone selectively antagonizes isoniazid-induced convulsions via GABA mechanism, not glycine. pmid:96460

  • The dose-response profile in mice is hierarchical: anticonvulsant activity appears at low, non-sedative doses, while muscle relaxation and sedation emerge at higher doses.supported

    Dose-dependent: anticonvulsant at low doses, muscle-relaxant and sedative at higher doses. pmid:96460

  • Claim in pharmacology — inconclusiveinconclusiveworking →

  • Claim in pharmacology — inconclusiveinconclusiveworking →

  • Peak serum concentrations of approximately 1.2 µg/mL occur 2–3 hours after a 250 mg oral dosesupported

    After 250 mg oral dose, peak serum concentration 1.2 µg/mL at Tmax 3h. After 5th consecutive daily dose, peak 1.9 µg/mL at Tmax 2h. pmid:10165

  • Hepatic metabolism accounts for >95% of elimination, with less than 5% of the parent compound excreted unchanged in urinesupported

    <1% excreted unchanged. pmid:21773

  • CYP3A4 is the primary metabolizing enzyme, producing the major metabolite 4ʹ-hydroxymethaqualone along with four additional monohydroxylated metabolites (2ʹ-OH, 3ʹ-OH, 2-OH, and 6-OH) and methaqualone-N1-oxidesupported

    Five major monohydroxy metabolites; 4'-hydroxymethaqualone is major urinary metabolite. CYP3A4 is primary metabolic enzyme; CYP2D6 and CYP2C19 not significant contributors. pmid:12900872

  • CYP3A4 is the primary metabolizing enzyme, producing the major metabolite 4ʹ-hydroxymethaqualone along with four additional monohydroxylated metabolites (2ʹ-OH, 3ʹ-OH, 2-OH, and 6-OH) and methaqualone-N1-oxidepartially supported

    Five monohydroxy metabolites identified. Main metabolite is conjugated 4'-hydroxymethaqualone. Methaqualone-N1-oxide confirmed as important metabolite. pmid:21773

  • CYP3A4 is the primary metabolizing enzyme, producing the major metabolite 4ʹ-hydroxymethaqualone along with four additional monohydroxylated metabolites (2ʹ-OH, 3ʹ-OH, 2-OH, and 6-OH) and methaqualone-N1-oxidepartially supported

    Five monohydroxy metabolites: 4'-OH-MQ (major), 2'-OH-MQ, 3'-OH-MQ, 2-OH-MQ, 6-OH-MQ. pmid:11589290

  • Metabolite excretion continues for at least 70 hours post-dose.supported

    Metabolite excretion ongoing at 70h. pmid:21773

  • The elimination half-life is reported as approximately 10 hours by White et al. following repeated 250 mg oral dosing, though pharmacological reference sources cite values of 20–60 hourssupported

    Half-life ~10h. No significant accumulation over 5 days. pmid:10165

  • Claim in pharmacology — inconclusiveinconclusiveworking →

summary13 · 11 ok
  • Claim in summary — inconclusiveinconclusiveworking →

  • Moderate lipophilicity (XLogP 2.5) facilitates efficient blood-brain barrier penetration.partially supported

    Review of quinazolinone pharmacology and structure-activity relationships. Covers CNS activity related to BBB penetration due to lipophilicity. molecules28030978

  • Controlled human studies confirmed high abuse liability relative to other sedatives, leading to progressive scheduling: Schedule II in the US (1973), then Schedule I (1984), with legal manufacture ceasing worldwidepartially supported

    Methaqualone 300 mg caused elevated scores on euphoria, physical sedation, and abuse liability scales in 24 recreational sedative users vs placebo. pmid:6130076

  • The compound retains research significance through 2024 cryo-EM structural studies resolving its unique GABAA binding site, and it persists as a major illicit drug in South Africa.partially supported

    Cryo-EM study localizing methaqualone and PPTQ binding sites at GABAA receptor transmembrane intersubunit interfaces targeted by propofol and etomidate. s41467-024-49471-y

  • The compound retains research significance through 2024 cryo-EM structural studies resolving its unique GABAA binding site, and it persists as a major illicit drug in South Africa.supported

    SACENDU surveillance network; methaqualone (Mandrax) one of the two most prevalent illicit drugs in South Africa 1997-1999. pmid:12144599

  • Methaqualone potentiates GABAA receptors through the transmembrane β(+)/α(−) subunit interface — the etomidate site — rather than through benzodiazepine, barbiturate, or neurosteroid binding sitessupported

    Acts through transmembrane beta+/alpha- subunit interface overlapping with etomidate site. mol.115.099291

  • It displays positive allosteric modulation at α1,2,3,5β2,3γ2S subtypes and a complex, multifaceted profile at δ-containing extrasynaptic receptors ranging from negative modulation to superagonism — a selectivity pattern without parallel among clinically used GABAergics.supported

    Methaqualone is a PAM at alpha1,2,3,5 beta2,3 gamma2S GABAA receptors; diverse functionalities at alpha4,6 subtypes. mol.115.099291

  • The subjective experience centers on sedation, muscle-relaxation, and a distinctive euphoria with prominent tactile components — peripheral paresthesia in lips and fingertips, grounded in GABA-mediated modulation of somatosensory cortex receptive fields. disinhibition and anxiety-suppression complete the core profilesupported

    Methaqualone alters receptive-field sizes of primary somatosensory cortical neurons via GABA-mediated inhibitory processes. Users report peripheral paresthesia and transient numbness in lips and fingertips. pmid:2311013

  • Mouse LD50 is 240 mg/kg intraperitoneally; overdose presents with respiratory depression, unconsciousness, and paradoxical convulsionspartially supported

    Mouse LD50 for methaqualone 240 mg/kg; naloxone increased LD50 to 416 mg/kg. pmid:493294

  • Claim in summary — inconclusiveinconclusiveworking →

  • Alcohol synergizes with methaqualone through pharmacodynamic sensitization persisting up to three days after a single dosepartially supported

    Ethanol increases duration of methaqualone hypnosis via pharmacodynamic sensitization (reduced minimum effective dose) not altered PK. pmid:644120

  • Tolerance develops through dual mechanisms: GABAA receptor adaptation and CYP3A4 enzyme induction — the latter producing the shortest antipyrine half-life reported for any drug-exposed group in clinical studies of dependent patientspartially supported

    Very high drug-metabolizing capacity on admission; marked drug tolerance. Induction of drug-metabolizing capacity contributed to tolerance. pmid:5085238

  • The elimination half-life remains disputed (10 hours vs 20–60 hours), likely reflecting two-compartment pharmacokinetics not fully resolved in published studies.supported

    Half-life ~10h. No significant accumulation over 5 days. pmid:10165

clinical-evidence9 · 4 ok
  • Claim in clinical-evidence — inconclusiveinconclusiveworking →

  • The most informative controlled human study is the abuse-liability assessment by Cole et al. (1982), a blinded crossover design comparing methaqualone (300 mg oral) against diazepam, buspirone, and placebo in 24 recreational sedative userssupported

    Methaqualone 300 mg caused elevated scores on euphoria, physical sedation, and abuse liability scales in 24 recreational sedative users vs placebo. Diazepam 20 mg showed some euphoriant effect. pmid:6130076

  • White et al. (1976): Measured serum methaqualone concentrations after repeated oral administration of the combination formulation (methaqualone + diphenhydramine) in human subjects. Established Tmax of 2–3 hours, peak concentration of ~1.2 µg/mL after 250 mg, and terminal half-life of ~10 hours with no evidence of accumulation on daily dosing.supported

    After 250 mg oral dose, peak serum concentration 1.2 µg/mL at Tmax 3h. After 5th consecutive daily dose, peak 1.9 µg/mL at Tmax 2h. Half-life ~10h. No significant accumulation over 5 days. pmid:10165

  • Claim in clinical-evidence — inconclusiveinconclusiveworking →

  • Claim in clinical-evidence — inconclusiveinconclusiveworking →

  • Claim in clinical-evidence — inconclusiveinconclusiveworking →

  • Naik et al. (1978) established methaqualone's anticonvulsant profile in mice: selective antagonism of isoniazid-induced (GABA-deficiency) convulsions but not strychnine-induced (glycinergic) convulsions, with a dose-dependent progression from anticonvulsant activity at non-sedative doses to muscle relaxation and sedation at higher doses.supported

    Methaqualone selectively antagonizes isoniazid-induced convulsions via GABA mechanism, not glycine. Dose-dependent: anticonvulsant at low doses, muscle-relaxant and sedative at higher doses. pmid:96460

  • Claim in clinical-evidence — inconclusiveinconclusiveworking →

  • Sexual risk and HIV: Bonner et al. (2022) found methaqualone use reduced the ability of young women to negotiate safer sex, increasing HIV risk. Tiemensma and Davies (2018) identified methaqualone as a substance implicated in drug-facilitated sexual assault in Cape Town.partially supported

    Methaqualone identified as substance used in drug-facilitated sexual assault. Toxicological screening not routinely available in clinical forensic practice in Western Cape. j.forsciint.2018.04.028

neuroscience7 · 5 ok
  • Claim in neuroscience — inconclusiveinconclusiveworking →

  • Haider and Oswald (1970) documented a delayed withdrawal syndrome 1–3 weeks after methaqualone overdose — insomnia, restlessness, elevated REM sleep, epileptic phenomena, and deliriumsupported

    Withdrawal syndrome can occur up to 1-3 weeks post-overdose with insomnia, restlessness, raised REM sleep, epileptic phenomena, delirium. pmid:4317051

  • Claim in neuroscience — inconclusiveinconclusiveworking →

  • Hicks et al. (1990) showed that methaqualone alters receptive-field sizes of neurons in primary somatosensory cortex (S1), expanding or contracting the area of skin surface from which individual neurons respondsupported

    Methaqualone alters receptive-field sizes of primary somatosensory cortical neurons via GABA-mediated inhibitory processes. pmid:2311013

  • The compound produces muscle relaxation at doses above the anticonvulsant threshold but below the sedative-hypnotic threshold, suggesting differential sensitivity of motor circuit GABAA receptors compared to cortical populations.supported

    Dose-dependent: anticonvulsant at low doses, muscle-relaxant and sedative at higher doses. pmid:96460

  • Methaqualone's euphoriant and reinforcing properties, confirmed by controlled human data, implicate GABAergic modulation of mesolimbic reward circuitrysupported

    Methaqualone 300 mg caused elevated scores on euphoria, physical sedation, and abuse liability scales in 24 recreational sedative users vs placebo. pmid:6130076

  • This phenomenon may involve selective depression of inhibitory interneurons at high concentrations (disinhibition of excitatory circuits) or engagement of the compound's negative modulatory activity at specific δ-containing receptor subtypes (e.g., α6β1δ).supported

    Diverse functionalities at alpha4,6 subtypes. mol.115.099291

pharmacokinetic-detail5 · 5 ok
  • ~10 hours: Measured by White et al. (1976) after repeated 250 mg oral dosing with no evidence of drug accumulationsupported

    Half-life ~10h. No significant accumulation over 5 days. pmid:10165

  • CYP3A4 is the primary enzyme responsible, with no significant contribution from CYP2D6 or CYP2C19supported

    CYP3A4 is primary metabolic enzyme; CYP2D6 and CYP2C19 not significant contributors. pmid:12900872

  • All five monohydroxylated metabolites display stereoselective formation, with enantiomeric excess detectable by chiral capillary electrophoresispartially supported

    Major metabolite 4'OH-MQ excreted almost exclusively as single enantiomer. Stereoselective metabolism characterized. pmid:11589290

  • Metabolites are excreted primarily as glucuronide conjugates, with ongoing urinary excretion detectable at 70 hours post-dose.supported

    Main metabolite is conjugated 4'-hydroxymethaqualone. Metabolite excretion ongoing at 70h. pmid:21773

  • Pregnancy alters methaqualone pharmacokinetics: half-life is prolonged during labour and shortened during active pregnancy compared to non-pregnant controls.supported

    Methaqualone half-life prolonged during labour; diminished in pregnancy compared to non-pregnant controls. pmid:6933942

comparative-pharmacology4 · 4 ok
  • The controlled human comparison (Cole et al. 1982) found methaqualone (300 mg) produced greater euphoria and higher abuse-liability scores than diazepam at its tested dose, suggesting a qualitatively different reinforcement profile.supported

    Methaqualone 300 mg caused elevated scores on euphoria, physical sedation, and abuse liability scales in 24 recreational sedative users vs placebo. Diazepam 20 mg showed some euphoriant effect. pmid:6130076

  • The critical structural distinction is that methaqualone and its quinazolinone analogs insert more deeply into the β(+)/α(−) intersubunit interface than either propofol or etomidate, as resolved by cryo-EMpartially supported

    Cryo-EM study localizing methaqualone and PPTQ binding sites at GABAA receptor transmembrane intersubunit interfaces targeted by propofol and etomidate. s41467-024-49471-y

  • Cross-tolerance between the two classes occurs through shared downstream GABAA-mediated neuroadaptation despite the different binding sites.supported

    Animals withdrawn from chronic Mandrax showed significant cross-tolerance to intracerebroventricularly administered pentobarbital — confirms cross-tolerance between methaqualone and barbiturates. pmid:4155651

  • The quinazolinone scaffold has produced at least one documented research chemical analog: SL-164, identified in a 2024 case report of intoxication requiring LC-QTOF-MS for identification because standard immunoassay panels did not detect itsupported

    Case report: 22-year-old with altered mental status after SL-164 (methaqualone analog) intoxication. Serum concentration 390 ng/mL. dta.3792

receptor-pharmacology4 · 3 ok
  • The hallmark of methaqualone's receptor pharmacology is a multifaceted profile across GABAA receptor subtypes — a selectivity pattern that defies simple classification as a universal GABAA potentiator.supported

    Methaqualone is a PAM at alpha1,2,3,5 beta2,3 gamma2S GABAA receptors; diverse functionalities at alpha4,6 subtypes. mol.115.099291

  • At δ-subunit-containing extrasynaptic receptors — mediators of tonic inhibition — methaqualone displays a complex and subunit-dependent range of activities:supported

    Diverse functionalities at alpha4,6 subtypes. mol.115.099291

  • Cryo-EM structural data (2024) resolved the methaqualone binding pose within the GABAA receptor at atomic resolutionsupported

    Cryo-EM study localizing methaqualone and PPTQ binding sites at GABAA receptor transmembrane intersubunit interfaces. s41467-024-49471-y

  • Claim in receptor-pharmacology — inconclusiveinconclusiveworking →

chemistry3 · 2 ok
  • Methaqualone belongs to the quinazolinone chemical class — nitrogen-containing heterocyclic compounds comprising a benzene ring fused to a pyrimidinone ringsupported

    Review of quinazolinone pharmacology and structure-activity relationships. molecules28030978

  • Claim in chemistry — inconclusiveinconclusiveworking →

  • The primary urinary metabolite, 4ʹ-hydroxymethaqualone, is excreted almost exclusively as a single enantiomer, reflecting the stereoselective orientation of the parent compound within the CYP3A4 active sitepartially supported

    Five major monohydroxy metabolites; 4'-hydroxymethaqualone is major urinary metabolite. CYP3A4 is primary metabolic enzyme. pmid:12900872

history3 · 0 ok
  • Claim in history — not_supportednot supportedworking →

  • Claim in history — inconclusiveinconclusiveworking →

  • Claim in history — inconclusiveinconclusiveworking →

effects-overview1 · 1 ok
  • This tactile component has a confirmed neural substrate in somatosensory cortex GABA modulationsupported

    Methaqualone alters receptive-field sizes of primary somatosensory cortical neurons via GABA-mediated inhibitory processes. Users report peripheral paresthesia and transient numbness in lips and fingertips. pmid:2311013

legal-status1 · 1 ok
  • Legal pharmaceutical manufacture ceased globally following US reclassification to Schedule I in 1984; all current methaqualone is clandestinely manufactured.partially supported

    Comprehensive review of controlled substances; explicitly names methaqualone as a Schedule I drug alongside heroin and LSD. neurolint13040059

3Sources

45 consumed · sorted by year · feeds = sections resting on it

Sources 1 to 30
yearsourcetierstatusfeeds
2026Prescription of Controlled Substances: Benefits and RisksPreuss CV, Kalava A, King KC, et al. · Neurology internationaldoi:10.3390/neurolint13040059moderateconsumed1 section
2024Associations between childbirth, gang exposure and substance use among young women in Cape Town, South AfricaBrowne FA, Carney T, Myers B, Bonner CP, Wechsberg WM · Substance Abuse Treatment, Prevention, and Policydoi:10.1186/s13011-024-00610-0moderateconsumedcited only
2024Methaqualoneurl:266a599ff70e3559weakconsumedcited only
2024Methaqualone Physical Properties - CAS 72-44-6url:4652b001ab326a86weakconsumedcited only
2024Methaqualone PubChem CID 6292 Propertiesurl:dcce4df4d4a7f91bweakconsumedcited only
2024Methaqualone Timelineurl:be1dc8ba6fabafc5weakconsumedcited only
2024Quaaludes: Uses, Effects and History of Abuseurl:08694ab1f4ee1ce6weakconsumedcited only
2024Step-By-Step Procedure to Identify Previously Unknown Compounds by LC-QTOF-MS Exemplified by an Intoxication With the Methaqualone Analog SL-164Fels H, Franz S, Dame T, Skopp G, Musshoff F · Drug Testing and Analysisdoi:10.1002/dta.3792weakconsumed1 section
2024Structural insights into GABAA receptor potentiation by QuaaludeChojnacka W, Teng J, Kim JJ, Jensen AA, Hibbs RE · Nature Communicationsdoi:10.1038/s41467-024-49471-ymoderateconsumed4 sections
2023Quinazolinones, the Winning Horse in Drug DiscoveryAlsibaee AM, Al-Yousef HM, AlSalem HS · Moleculesdoi:10.3390/molecules28030978moderateconsumed2 sections
2022Mandrax use, sexual risk, and opportunities for pre-exposure prophylaxis among out-of-school adolescent girls and young women in Cape Town, South AfricaBonner CP, Browne FA, Carney T, Shangase N, Ndirangu JW, Myers B, Wechsberg WM · South African Medical Journalpmid:35587247moderateconsumed1 section
2021Sedative-Hypnotic Agents That Impact Gamma-Aminobutyric Acid Receptors: Focus on Flunitrazepam, Gamma-Hydroxybutyric Acid, Phenibut, and SelankDoyno CR, White CM · Journal of Clinical Pharmacologydoi:10.1002/jcph.1922strongconsumed4 sections
2021The white pipe keeps burningurl:fd8a1bfa2aa26781weakconsumedcited only
2018Functional properties and mechanism of action of PPTQ, an allosteric agonist and low nanomolar positive allosteric modulator at GABAA receptorsMadjroh N, Olander ER, Bundgaard C, Soderhielm PC, Jensen AA · Biochemical Pharmacologydoi:10.1016/j.bcp.2017.11.006moderateconsumed1 section
2018Investigating drug-facilitated sexual assault at a dedicated forensic centre in Cape Town, South AfricaTiemensma M, Davies B · Forensic Science Internationaldoi:10.1016/j.forsciint.2018.04.028moderateconsumed2 sections
2015A Multifaceted GABAA Receptor Modulator: Functional Properties and Mechanism of Action of the Sedative-Hypnotic and Recreational Drug Methaqualone (Quaalude)Hammer H, Bader BM, Ehnert C, Bundgaard C, Bunch L, Hoestgaard-Jensen K, Schroeder OH, Bastlund JF, Gramowski-Voss A, Jensen AA · Molecular Pharmacologydoi:10.1124/mol.115.099291moderateconsumed4 sections
2005Cannabis and other drug use among trauma patients in three South African cities, 1999-2001Parry CD, Pluddemann A, Donson H, Sukhai A, Marais S, Lombard C · South African Medical Journalpmid:16100892moderateconsumedcited only
2004Substance abuse and major trauma in JohannesburgBowley DM, Rein P, Cherry R, Vellema J, Snyman T, Boffard KD · South African Journal of Surgerypmid:15181707moderateconsumed1 section
2004The 3-metros study of drugs and crime in South Africa: findings and policy implicationsParry CD, Pluddemann A, Louw A, Leggett T · American Journal of Drug and Alcohol Abusepmid:15083560moderateconsumedcited only
2003Assessment of the stereoselective metabolism of methaqualone in man by capillary electrophoresisProst F, Thormann W · Electrophoresispmid:12900872moderateconsumed3 sections
2002The South African Community Epidemiology Network on Drug Use (SACENDU) project, phases 1-8--cannabis and MandraxBhana A, Parry CD, Myers B, Pluddemann A, Morojele NK, Flisher AJ · South African Medical Journalpmid:12197197moderateconsumed2 sections
2002The South African Community Epidemiology Network on Drug Use (SACENDU): description, findings (1997-99) and policy implicationsParry CD, Bhana A, Pluddemann A, Myers B, Siegfried N, Morojele NK, Flisher AJ, Kozel NJ · Addictionpmid:12144599moderateconsumed1 section
2001Enantiomeric analysis of the five major monohydroxylated metabolites of methaqualone in human urine by chiral capillary electrophoresisProst F, Thormann W · Electrophoresispmid:11589290moderateconsumed2 sections
1990Receptive-field size of S1 cortical neurones is altered by methaqualone via a GABA mechanismHicks TP, Kaneko T, Oka JI · Canadian Journal of Neurological Sciencespmid:2311013moderateconsumed3 sections
1983Clinical aspects of drug intoxication: barbiturates and a potpourri of other sedatives, hypnotics, and tranquilizersGary NE, Tresznewsky O · Heart and Lungpmid:6550044moderateconsumed1 section
1982Assessment of the abuse liability of buspirone in recreational sedative usersCole JO, Orzack MH, Beake B, Bird M, Bar-Tal Y · Journal of Clinical Psychiatrypmid:6130076moderateconsumed5 sections
1980Ethanol-sedative hypnotic interactions: in vitro studies on Na-K-activated adenosine triphosphataseHo CC, Ho AK · Archives Internationales de Pharmacodynamie et de Therapiepmid:6260047moderateconsumed1 section
1980Research on pharmacokinetics during pregnancyNoschel H, Peiker G, Voigt R, Meinhold P, Muller B, Schroder S, Bonow A · Archives of Toxicology Supplementpmid:6933942moderateconsumed2 sections
1979Toxic interactions of ethanol with other central depressants: antagonism by naloxone to narcosis and lethalityHo AK, Ho CC · Pharmacology, Biochemistry, and Behaviorpmid:493294moderateconsumed2 sections
1978Interaction of ethanol with amylobarbitone, phenobarbitone and methaqualoneTilstone WJ, Reavey PC · Research Communications in Chemical Pathology and Pharmacologypmid:644120moderateconsumed2 sections
Show all 46 sources — 16 more
Sources 31 to 46
yearsourcetierstatusfeeds
1978Involvement of gamma-amino butyric acid (GABA) in the anticonvulsant action of methaqualoneNaik SR, Naid PR, Sheth UK · Psychopharmacologypmid:96460moderateconsumed4 sections
1977The effect of ethanol on residual plasma methaqualone concentrations and behaviour in volunteers who have taken MandraxRoden S, Harvey P, Mitchard M · British Journal of Clinical Pharmacologypmid:861141moderateconsumed1 section
1977The influence of alcohol on the persistent effects on human performance of the hypnotics Mandrax and NitrazepamRoden S, Harvey P, Mitchard M · International Journal of Clinical Pharmacology and Biopharmacypmid:892953moderateconsumed1 section
1977Urinary excretion pattern of methaqualone metabolites in manEricsson O, Danielsson B · Drug Metabolism and Dispositionpmid:21773moderateconsumed2 sections
1976Effect of subacute treatment with hypnotics, alone or in combination with alcohol, on psychomotor skills related to drivingSaario I, Linnoila M · Acta Pharmacologica et Toxicologicapmid:773108moderateconsumed1 section
1976Serum concentrations of methaqualone after repeated oral doses of a combination formulation to human subjectsWhite C, Doyle E, Chasseaud LF, Taylor T · European Journal of Clinical Pharmacologypmid:10165moderateconsumed4 sections
1975Methaqualone: tolerance and physical dependence in miceAlpern HP, Greer CA, Stripling JS, Collins AC, Olson RK · Psychopharmacologiapmid:1239784moderateconsumed1 section
1974A study of the factors affecting the sleeping time following intracerebroventricular administration of pentobarbitone sodium: effect of prior administration of centrally active drugsStevenson IH, Turnbull MJ · British Journal of Pharmacologypmid:4155651moderateconsumed2 sections
1974Absorption and clearance of secobarbital, heptabarbital, methaqualone, and ethinamateClifford JM, Cookson JH, Wickham PE · Clinical Pharmacology and Therapeuticspmid:4604053moderateconsumed1 section
1974An experimental investigation of dependence liability of methaqualone in ratsKohli RP, Singh N, Kulshrestha VK · Psychopharmacologiapmid:4857557moderateconsumed1 section
1974Methaqualone pharmacokinetics after single- and multiple-dose administration in manNayak RK, Smyth RD, Chamberlain JH, Polk A, DeLong AF, Herczeg T, Chemburkar PB, Joslin RS, Reavey-Cantwell NH · Journal of Pharmacokinetics and Biopharmaceuticspmid:4427217moderateconsumed2 sections
1973Acute drug poisoning in the adultRuedy J · Canadian Medical Association Journalpmid:4742490moderateconsumed1 section
1972Drug-metabolizing capacity in states of drug dependence and withdrawalBallinger B, Browning M, O'Malley K, Stevenson IH · British Journal of Pharmacologypmid:5085238weakconsumed2 sections
1972Plasma levels and absorption of methaqualone after oral administration to manMorris RN, Gunderson GA, Babcock SW, Zaroslinski JF · Clinical Pharmacology and Therapeuticspmid:5053813moderateconsumed1 section
1970Late brain recovery processes after drug overdoseHaider I, Oswald I · British Medical Journalpmid:4317051weakconsumed2 sections
—Searched ClinicalTrials.gov for "methaqualone" — no resultsabsenceno results—

4Docket

one filing per activity — decisions, correspondence, reports

  1. 0012026-05-12revisionRevision 1

    Initial LLM generation (v5 pipeline, wiki, prose phase)

    psx:substance/methaqualone/version/1
  2. 0022026-06-04proposal37 value proposals approved together

    one review action inferred from a shared reviewer and instant — the graph records one activity per proposal

    37 items in this filing

    • contraindication · other
    • contraindication · other
    • contraindication · other
    • contraindication · respiratory
    • contraindication · neurological
    • contraindication · hepatic
    • contraindication · pregnancy_breastfeeding
    • contraindication · psychiatric
    • contraindication · other
    • dose_tier · threshold
    • dose_tier · light
    • dose_tier · common
    • dose_tier · strong
    • dose_tier · heavy
    • timeline · oral · onset
    • timeline · oral · come_up
    • timeline · oral · peak
    • timeline · oral · resolution
    • timeline · oral · afterglow
    • timeline · smoked · onset
    • timeline · smoked · peak
    • timeline · smoked · resolution
    • toxicity
    • dependence · full
    • withdrawal
    • tolerance
    • dosage · oral
    • dosage · smoked
    • duration · oral · onset
    • duration · oral · come_up
    • duration · oral · peak
    • duration · oral · offset
    • duration · oral · total
    • duration · oral · aftereffects
    • duration · smoked · onset
    • duration · smoked · total
    psx:substance/methaqualone/proposal/contraindication/3e7492db-37b2-4d13-80e0-2201a00651e5
  3. 0032026-06-04publicationPublication — backfill

5Issued documents

what the notice, info card and emergency page said, by hash

Issued documents
documentcontent hashissuedfrom versionsuperseded
info_cardd9400beb6685f63410f1fd2f…2026-10-19 20:32Revision 1current
emergencydcd2ca271fbe095dc7fb6211…2026-09-04 04:31Revision 1current
info_card195ec067904e88199b529285…2026-09-04 04:31Revision 1superseded2026-10-19
noticefcf8b8c7fe13ad38b2e12e66…2026-09-04 04:31Revision 1current