WARNINGMIXING OR WITHDRAWAL CAN BE DANGEROUS
Ordinary doses in combination with other depressants can fatally stop breathing. After prolonged dependency, stopping suddenly can also cause seizures or delirium; seek medical help.
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Quazepam
Quazepam is a long-acting depressant of the 1,4-benzodiazepine class, used for the short-term treatment of insomnia. It promotes sleep onset and maintenance1 without disrupting sleep architecture and has relatively selective hypnotic and anticonvulsant effects. Developed by the Schering Corporation in the 1970s2, it entered medical use in 1985. Quazepam can impair motor function3, is habit-forming3, and has the potential for misuse, including recreational use and prolonged use against medical advice.
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Duration
Subjective Effects
Pharmacology
Pharmacodynamics
Quazepam positively modulates GABA-A receptors at the benzodiazepine binding site, strengthening the inhibitory action of endogenous GABA by increasing chloride-channel opening frequency. It preferentially targets receptors containing the α1 subunit, which supports its sleep-promoting action. Its active metabolites contribute to its pharmacological effects, although their receptor selectivity differs. Quazepam also has a reported modulatory interaction with translocator protein.
Pharmacokinetics
After oral administration, quazepam has an absorption half-life of approximately 30 minutes3 and reaches peak plasma concentrations of approximately 20 ng/mL around 2 hours later. Another report gives an absorption half-life of 0.4 hours and a plasma peak at 1.75 hours. It undergoes extensive hepatic metabolism, primarily through CYP3A4, with smaller contributions from CYP2C9, CYP2C19, and FMO1, producing active metabolites through sequential metabolism. It is also classified as a CYP2B6 inhibitor.4 Quazepam and its two major metabolites are more than 95% bound to plasma proteins.3 Its elimination half-life is reported as approximately 39 hours,5 with other reports giving 25 hours or a range of 27-41 hours. The two active metabolites have reported elimination half-lives of approximately 39 and 73 hours,5 while another report gives 28 and 79 hours. Quazepam and its long-lived metabolites can accumulate with repeated administration, including accumulation of an active metabolite in older adults. Quazepam and its active metabolites enter breast milk.6 Following radiolabeled administration, approximately 31% of the dose was recovered in urine and 23% in feces over five days, with only trace amounts of unchanged quazepam in urine.3
Interactions
An unlisted combination is an unknown one, not a safe one. Check a dedicated combination chart before mixing.
Tolerance
Tolerance timelines are rules of thumb, not exact schedules, and vary widely between individuals and use patterns.
Harm Potential
Addiction & Dependence
Psychological
Quazepam is habit-forming and has misuse potential,3 including recreational use to achieve intoxication and continued long-term use against medical advice.
Physical
Quazepam can produce withdrawal symptoms,3 including rebound insomnia, although these are less pronounced than with other benzodiazepines; gradual discontinuation is recommended after more than four weeks of use to reduce the risk of severe withdrawal. In animal studies involving very high doses for prolonged periods of up to 52 weeks, abrupt discontinuation caused severe withdrawal with excitability, hyperactivity, and convulsions; withdrawal-related convulsions killed two monkeys.
Toxicity
Repeated quazepam administration produced marked next-day impairment in one study, while another found significant balance impairment and unstable posture after administration.
Seizure Risk
Abrupt discontinuation after prolonged, very-high-dose quazepam exposure in animal studies caused withdrawal convulsions, including fatal convulsions in two monkeys.
History & Culture
Quazepam was developed by the Schering Corporation in the 1970s and was patented in 1970. It was first approved in the United States in 19853 and entered medical use that year as a treatment for…
Legality
International
Quazepam has approved and illicit regulatory groupings.
By Country
United StatesIllegalReferences
Citations
Article Status
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