Oxazepam (Monograph)

Drug class: Benzodiazepines
VA class: CN302
Chemical name: 7 chloro-1,3-dihydro-3-hydroxy-5-phenyl-2H-1,4-benzodiazepin-2-one
Molecular formula: C₁₅H₁₁ClN₂O₂
CAS number: 604-75-1

Medically reviewed by Drugs.com on Sep 16, 2024. Written by ASHP.

Warning

Concomitant use of benzodiazepines and opiates may result in profound sedation, respiratory depression, coma, and death.
Reserve concomitant use for patients in whom alternative treatment options are inadequate; use lowest effective dosages and shortest possible duration of concomitant therapy and monitor closely for respiratory depression and sedation. (See Specific Drugs under Interactions.)

A boxed warning has been included in the prescribing information for all benzodiazepines describing risks of abuse, misuse, addiction, physical dependence, and withdrawal reactions.
Abuse and misuse can result in overdose or death, especially when benzodiazepines are combined with other medicines, such as opioid pain relievers, alcohol, or illicit drugs.
Assess a patient’s risk of abuse, misuse, and addiction. Standardized screening tools are available ([Web]).
To reduce risk of acute withdrawal reactions, use a gradual dose taper when reducing dosage or discontinuing benzodiazepines. Take precautions when benzodiazepines are used in combination with opioid medications.

Introduction

Benzodiazepine. Anxiolytic, sedative.

Uses for Oxazepam

Alcohol Withdrawal

Relief of agitation and tremor and prevention or symptomatic relief of delirium tremens and hallucinations associated with acute alcohol withdrawal.

Anxiety Disorders

Management of anxiety disorders and short-term relief of anxiety or anxiety associated with depressive symptoms.

One of several preferred benzodiazepines in geriatric patients and patients with liver disease (because of its short elimination half-life and lack of active metabolites).

Oxazepam Dosage and Administration

General

Use the smallest effective dosage (especially in geriatric or debilitated patients and in those with low serum albumin) to avoid oversedation.
In patients who have received prolonged (e.g., for several months) therapy, avoid abrupt discontinuance, since manifestations of withdrawal can be precipitated; gradually taper dosage.

Anxiety

Periodically reassess the usefulness of the drug. Efficacy beyond 4 months not systematically evaluated. Administer for the shortest possible period of time; frequent dosage adjustments may be required.

Administration

Oral Administration

Administer orally in divided doses, generally 3 or 4 times daily.

Dosage

Pediatric Patients

Anxiety Disorders

Oral

Children 6–12 years of age: Dosage not clearly established.

Adults

Alcohol Withdrawal

Oral

15–30 mg 3 or 4 times daily.

Anxiety Disorders

Oral

Mild to moderate anxiety: 10–15 mg 3 or 4 times daily.

Severe anxiety: 15–30 mg 3 or 4 times daily.

Special Populations

Hepatic Impairment

No specific dosage recommendations.

Renal Impairment

No specific dosage recommendations.

Geriatric Patients

Initially, 10 mg 3 times daily. Increase dosage to 15 mg 3 or 4 times daily if needed and tolerated. Use the smallest effective dosage to avoid oversedation.

Other Populations

Use the smallest effective dosage in debilitated patients and patients with low serum albumin concentrations to avoid oversedation.

Cautions for Oxazepam

Contraindications

Known hypersensitivity to oxazepam.
Many manufacturers state that benzodiazepines are contraindicated in patients with acute angle-closure glaucoma but may be administered to patients with open-angle glaucoma who are receiving appropriate therapy; however, clinical rationale for this contraindication has been questioned.

Warnings/Precautions

Warnings

Concomitant Use with Opiates

Concomitant use of benzodiazepines, including oxazepam, and opiates may result in profound sedation, respiratory depression, coma, and death. Substantial proportion of fatal opiate overdoses involve concurrent benzodiazepine use.

Reserve concomitant use of oxazepam and opiates for patients in whom alternative treatment options are inadequate. (See Specific Drugs under Interactions.)

CNS Effects

Performance of activities requiring mental alertness and physical coordination may be impaired.

Concurrent use of other CNS depressants may cause additive or potentiated CNS depression. (See Concomitant Use with Opiates under Cautions and also see Specific Drugs under Interactions.)

Psychiatric Indications

Avoid use in patients with depressive neuroses or psychotic reactions in which anxiety is not prominent.

Abuse Potential

Possible tolerance, psychologic dependence, and physical dependence following prolonged use.

Patients with a history of drug or alcohol dependence or abuse are at risk of habituation or dependence; use only with careful surveillance in such patients.

Withdrawal Syndrome

Abrupt discontinuance may result in symptoms of withdrawal (similar to barbiturates). Symptoms may be relieved by tapering the dosage.

Fetal/Neonatal Morbidity

Retrospective studies suggest increased risk of congenital malformations in infants of mothers who received anxiolytics (chlordiazepoxide, diazepam, meprobamate) during the first trimester of pregnancy. Since use of anxiolytics is rarely urgent, their use during the first trimester almost always should be avoided.

General Precautions

Hypotension

Hypotension reported rarely. Administer with caution to patients in whom a drop in BP might lead to cardiac complications, particularly geriatric patients.

Suicide

Use with caution in depressed patients; potential for suicidal tendencies. Prescribe and dispense drug in the smallest feasible quantity.

Laboratory Testing

Monitor blood counts and liver function tests periodically during prolonged therapy. Leukopenia and hepatic dysfunction (including jaundice) reported rarely.

Specific Populations

Pregnancy

Category D. (See Fetal/Neonatal Morbidity under Cautions.)

Lactation

Many benzodiazepines are distributed into milk. Not known whether oxazepam is distributed into milk. Discontinue nursing or the drug.

Pediatric Use

Safety and efficacy not established in children <6 years of age.

Dosage for children 6–12 years of age not clearly established.

Geriatric Use

Insufficient experience in patients ≥65 years of age to determine whether geriatric patients respond differently than younger adults. Possibility of greater sensitivity to the drug (e.g., sedation, hypotension, paradoxical excitation) in some geriatric individuals.

Select initial dosage at the lower end of the usual range because of potential for greater sensitivity and age-related decreases in hepatic or renal function. (See Geriatric Patients under Dosage and Administration.)

Hepatic Impairment

Use with caution.

Renal Impairment

Use with caution.

Common Adverse Effects

Drowsiness, dizziness, vertigo, headache.

Drug Interactions

Specific Drugs

Drug

Interaction

Comments

CNS depressants (e.g., alcohol, anticonvulsants)

Additive CNS effect

Use with caution to avoid overdosage; dosage reduction or discontinuance of CNS depressant may be necessary

Avoid alcohol use

Contraceptives, oral

Apparent increase in oxazepam metabolism

Clinical importance not established

Opiate agonists and partial agonists

Risk of profound sedation, respiratory depression, coma, or death

Whenever possible, avoid concomitant use

Opiate analgesics: Use concomitantly only if alternative treatment options are inadequate; use lowest effective dosages and shortest possible duration of concomitant therapy; monitor closely for respiratory depression and sedation

In patients receiving oxazepam, initiate opiate analgesic, if required, at reduced dosage and titrate based on clinical response

In patients receiving an opiate analgesic, initiate oxazepam, if required, at lower dosage than indicated in the absence of opiate therapy and titrate based on clinical response

Opiate antitussives: Avoid concomitant use

Consider offering naloxone to patients receiving benzodiazepines and opiates concomitantly

Oxazepam Pharmacokinetics

Absorption

Bioavailability

Readily absorbed from the GI tract, with peak plasma concentration usually attained within about 3 hours.

Distribution

Extent

Benzodiazepines are widely distributed into body tissues and cross the blood-brain barrier.

Oxazepam crosses the placenta.

Benzodiazepines generally are distributed into milk. Not known whether oxazepam is distributed into milk.

Plasma Protein Binding

Benzodiazepines are highly bound to plasma proteins.

Elimination

Metabolism

Conjugated with glucuronic acid in the liver to form a single, major inactive metabolite.

Elimination Route

Excreted principally in urine.

Half-life

8.2 hours (range: 3–21 hours).

Special Populations

Hepatic impairment: Pharmacokinetics not altered substantially in patients with cirrhosis.

Geriatric patients >80 years of age: Half-life is prolonged. Age <80 years does not appear to substantially alter pharmacokinetics.

Benzodiazepines are not appreciably removed by hemodialysis.

Stability

Storage

Oral

Capsules

Tight, light-resistant container at 20–25°C; protect from moisture.

Actions

Effects appear to be mediated through the inhibitory neurotransmitter GABA; the site and mechanism of action within the CNS appear to involve a macromolecular complex (GABA_A-receptor-chloride ionophore complex) that includes GABA_A receptors, high-affinity benzodiazepine receptors, and chloride channels.

Advice to Patients

Risk of potentially fatal additive effects (e.g., profound sedation, respiratory depression, coma) if used concomitantly with opiates either therapeutically or illicitly. Avoid concomitant use of opiate antitussives; also avoid concomitant use of opiate analgesics unless use is supervised by clinician.
Potential for drug to impair mental alertness or physical coordination; avoid driving or operating machinery until effects on individual are known.
Importance of informing clinicians of any behavioral or mental changes, memory impairment, tolerance, or dependence/withdrawal symptoms.
Importance of taking only as prescribed; do not increase dosage or duration of therapy or abruptly discontinue drug unless otherwise instructed by a clinician.
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, and alcohol consumption.
Importance of informing clinicians about any concomitant illnesses, particularly depression.
Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.
Importance of informing patients of other important precautionary information. (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Subject to control under the Federal Controlled Substances Act of 1970 as a schedule IV (C-IV) drug.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name