Home / Drugs / Starting with O /
indicationFor the treatment of anxiety disorders and alcohol withdrawal.
pharmacologyOxazepam is believed to stimulate GABA receptors in the ascending reticular activating system. Since GABA is inhibitory, receptor stimulation increases inhibition and blocks both cortical and limbic arousal following stimulation of the brain stem reticular formation.
mechanism of actionSimilar to other benzodiazepines, oxazepam exerts its anxiolytic effects by potentiating the effect of gamma-aminobutyric acid (GABA) on GABA-A receptors through a cooperative mechanism of action. GABA receptors are ionotropic chloride-linked channel receptors that produce inhibitory postsynaptic potentials. When activated by GABA, the GABA receptor/chloride ionophore complex undergoes a conformational change that allows the passage of chloride ions through the channel. Benzodiazepines are believed to exert their effect by increasing the effect of GABA at its receptor. Benzodiazepine binding increases chloride conductance in the presence of GABA by increasing the frequency at which the channel opens. In contrast, barbiturates increase chloride conductance in the presence of GABA by prolonging the time in which the channel remains open. There are 18 subtypes of the GABA receptor subunits. The α2 subunit of the α2β3γ2 receptor complex is thought to mediate anxiolytic effects while the α1 subunit of the α1β2γ2 receptor complex is thought to mediate sedative, anticonvulsant and anterograde amnesia effects.
toxicitySymptoms of overdose include confusion, drowsiness, and lethargy.
biotransformationNo active metabolites. Metabolized via conjugation prior to elimination.
absorptionWell absorbed from the gastrointestinal tract following oral administration. Time to peak concentration = 2-4 hours. Onset of action is slow, > 3 hours, following oral administration.
half life5-15 hours
route of eliminationThis product has a single, major inactive metabolite in man, a glucuronide excreted in the urine.
drug interactionsClozapine: Increased risk of toxicity
Kava: Kava may increase the effect of the benzodiazepine, oxazepam.
Triprolidine: The CNS depressants, Triprolidine and Oxazepam, may increase adverse/toxic effects due to additivity. Monitor for increased CNS depressant effects during concomitant therapy.