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Alprazolam
- indication:For the management of anxiety disorder or the short-term relief of symptoms of anxiety and for the treatment of panic disorder, with or without agoraphobia.
- pharmacologypharmacology:
- mechanism: Benzodiazepines bind nonspecifically to benzodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA<sub>A</sub>) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of the inhibitory neurotransmitter GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.
- toxicity: Oral, mouse: LD<sub>50</sub>=1020 mg/kg. Symptoms of overdose include confusion, coma, impaired coordination, sleepiness, and slowed reaction time.
- absorprion: Readily absorbed from the gastrointestinal tract. Bioavailability is 80-90%.
- halflife: 6.3-26.9 hours
- roouteelimination: Alprazolam and its metabolites are excreted primarily in the urine.
- volumedistribution:
- clearance: * 2.13 +/- 0.54 mL/min/kg [CYP3A inducers] * 0.90 +/- 0.21 mL/min/kg [without CYP3A inducers]