Oxazepam

7-chloro-1,3-dihydro-3-hydroxy-5-phenyl-2H-1,4-benzodiazepin-2-one

Serax, Serepax, Seresta, Sobril, Alepam

Psychoactive Class

Depressant Anxiolytic Sedative GABAergic Muscle Relaxant

Chemical Class

Oxazepam is an intermediate-acting benzodiazepine¹ prescribed for the treatment of anxiety disorders², panic disorders, alcohol withdrawal², and insomnia¹. It is characterized by relatively low potency compared to other benzodiazepines, a slow onset of action, and a simple metabolic profile that makes it less susceptible to variability based on age or liver function¹. It is notably an active metabolite of both diazepam and temazepam. Higher doses may produce amnesia and lowered inhibitions.

Dosage & Duration

Dosage

Threshold~5 mg

Light5-10 mg

Moderate10-30 mg

Strong30-45 mg

Heavy45+ mg

Duration

Onset60-120 minutes

After Effects1-10 hours

Total4-6 hours

Half-life

6-9 hours

Subjective Effects

The oxazepam experience is dominated by calm, physical relaxation, and relief from anxiety, with essentially no sensory alteration. As a slow-onset, relatively mild benzodiazepine, its effects build gradually and center on sedation and a dampening of emotional intensity rather than any recreational high. At higher doses, inhibitions loosen and memory of the period after ingestion becomes patchy or absent.

Physical

Muscle relaxation and a heavy, sedated body feeling are the primary physical effects, accompanied by suppression of spasms and seizures. Fatigue, motor impairment, muscle weakness, headaches, and, at high doses, slowed breathing have been reported.

Sedation

Sedation is central to the experience, shading into sleep induction at higher doses.

Uncomfortable

DizzinessHeadaches

Cognitive

The headspace is calm and emotionally muted, with slowed thinking, reduced anxiety, and lowered inhibitions. Confusion and anterograde amnesia become increasingly likely as the dose rises.

Suppressions

Cognitive effects are broadly suppressive, reflecting reduced signaling between neurons across the central nervous system.

Reagent Testing

Loading reagent data

Expected colorimetric results are being prepared.

Pharmacology

Pharmacodynamics

Oxazepam acts as a positive allosteric modulator of GABA-A receptors, binding at the benzodiazepine site located at the interface between the alpha and gamma subunits of the receptor. This binding potentiates the inhibitory effects of endogenous GABA in the central nervous system.³ Oxazepam also acts as an agonist at the translocator protein and has been shown to suppress cortisol levels.⁴

Pharmacokinetics

Oxazepam is metabolized through a relatively simple pathway involving direct glucuronidation, without requiring hepatic oxidation.² The S-enantiomer is glucuronidated by UGT2B15, while the R-enantiomer is processed by UGT2B7 and UGT1A9, yielding a single major inactive glucuronide conjugate.⁵⁶ Oxazepam itself is an active metabolite formed during the breakdown of diazepam, nordazepam, and temazepam, and it undergoes very little additional biotransformation following absorption. The mean elimination half-life is approximately 8.2 hours, with a reported range of 6 to 9 hours.²⁷

Interactions

Dangerous

Highest risk

These combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.

AlcoholGHB/GBLOpioidsTramadol

Unsafe

Avoid

There is considerable risk of physical harm when taking these combinations, they should be avoided where possible.

DiphenhydraminePCP

Caution

Use caution

These combinations are not usually physically harmful, but may produce undesirable effects, such as physical discomfort or overstimulation. Extreme use may cause physical health issues. Synergistic effects may be unpredictable. Care should be taken when choosing to use this combination.

DXMKetamineMXE

TripSit

Tolerance

Full Tolerance

Tolerance develops with regular use, typically within 4-6 weeks of continuous administration. As with other benzodiazepines, habituation can lead to significantly elevated dose requirements compared to initial effective doses.

Cross Tolerance

Benzodiazepines, Other GABAergic depressants

Baseline Reset

Following prolonged use, gradual dose tapering under medical supervision is required rather than abrupt discontinuation. Complete tolerance reset timelines are not well-documented but extended abstinence periods are typically necessary.

Harm Potential

Addiction & Dependence

Psychological

Moderate

Oxazepam has documented abuse potential as a benzodiazepine, though its slow absorption and onset of action result in relatively lower abuse potential compared to faster-acting benzodiazepines such as temazepam, flunitrazepam, or triazolam.⁸ Misuse, defined as taking the drug to achieve a high or continuing use against medical advice, has been documented.⁹

Physical

High

Physical dependence develops with regular use, even at standard dosages and after relatively short-term use.¹⁰ Withdrawal symptoms are similar to those seen with alcohol and barbiturate withdrawal, including abdominal and muscle cramps, seizures, depression, insomnia, sweating, tremors, nausea, vomiting, and potentially hallucinations.⁹ Withdrawal should be medically supervised with gradual dose reduction.⁹

Toxicity

Respiratory

Respiratory depression may occur in overdose or when combined with other CNS depressants;⁹ at typical doses, significant respiratory effects are uncommon except in patients with pre-existing pulmonary conditions such as COPD or limited pulmonary reserve.

Cardiovascular

Hypotension may rarely occur during use; cardiovascular toxicity is occasionally observed in overdose situations.

Psychosis Risk

Paradoxical reactions including excitement, confusion, aggression, outbursts of anger, and restlessness may occur as side effects.⁹ Hallucinations have been reported primarily as a withdrawal symptom rather than during active use.

Seizure Risk

Oxazepam itself has anticonvulsant properties as a benzodiazepine. However, seizures are a significant risk during withdrawal, particularly after prolonged use or abrupt discontinuation.⁹ Some benzodiazepines may trigger seizures in individuals with epilepsy. Flumazenil administration in long-term users may also precipitate seizures.⁹

History & Culture

Oxazepam was patented in 1962 and received approval for medical use in 1964. The compound became one of the most commonly prescribed benzodiazepines in multiple countries during the late 20th century.…

Legality

International

1961 Single Convention: oxazepam is not scheduled.

1971 Convention on Psychotropic Substances: Schedule IV.

1988 Convention: oxazepam is not listed in precursor Tables I or II.

By Country

United StatesPrescription onlySchedule IV controlled substance

21 CFR § 1308.14(c); 21 USC § 829(b)²⁴

Oxazepam is federally listed in Schedule IV; Schedule IV prescription drugs may be dispensed only pursuant to a conforming prescription.

CanadaPrescription onlySchedule IV targeted substance

Controlled Drugs and Substances Act, Schedule IV; Benzodiazepines and Other Targeted Substances Regulations (SOR/2000-217), Schedule 1¹⁸¹⁹²⁰

Oxazepam is expressly listed in Schedule IV to the Controlled Drugs and Substances Act and in Schedule 1 of the Benzodiazepines and Other Targeted Substances Regulations. These federal controls support normalizing the existing prescription-medication entry to prescription_only while preserving its existing pharmaceutical context.

New ZealandPrescription onlyControlled prescription medicine

Misuse of Drugs Regulations 1977²²

Current New Zealand controlled-drug regulations expressly list oxazepam and regulate its prescribing and supply.

AustraliaPrescription onlySchedule 4 prescription-only medicine

Therapeutic Goods (Poisons Standard—June 2026) Instrument 2026, Schedule 4¹⁷

The current federal Poisons Standard lists oxazepam in Schedule 4, the prescription-only schedule.

GermanyPrescription onlyAnlage III controlled medicine

Betäubungsmittelgesetz, Anlage III; Betäubungsmittel-Verschreibungsverordnung²¹

Oxazepam is expressly listed in Anlage III of the federal narcotics law and is subject to controlled prescribing.

United KingdomPrescription onlySchedule 4 Part I controlled drug

Misuse of Drugs Regulations 2001, Schedule 4 Part I²³

Oxazepam is expressly listed in Schedule 4 Part I of the current controlled-drugs regulations.

References

Source Pages

Citations

Automated synthesis
Information aggregated and synthesized using an autonomous workflow built by Josie Kins.

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