Pharmacology.
Alprazolam is a triazolobenzodiazepine that is equal in efficacy to other benzodiazepines for generalized anxiety disorder but more effective in the treatment of panic disorder. Although alprazolam has some efficacy in major depression, it is less effective than heterocyclic antidepressants.
Adult Dosage.
PO for generalized anxiety disorder 0.25 mg tid initially, increasing gradually to 4 mg/day. PO for panic disorder 0.5 mg tid is recommended initially; most panic patients require 5-6 mg/day, and occasionally 10 mg/day can be needed for full response.
SL alprazolam tablets can be administered
SL with no difference from oral administration in onset, peak, or pharmacokinetics. Discontinuation decrease the daily dosage by no more than 0.5 mg/day q 3 days until the daily dosage reaches 2 mg and then decrease dosage in 0.25 mg/day increments q 3 days.
Dosage Forms.
Tab 0.25, 0.5, 1, 2 mg; Soln 0.1, 1 mg/mL.
Pharmacokinetics.
Like diazepam, alprazolam has a rapid onset of effect after oral administration, but its shorter half-life requires tid administration. The halflife is 11 hr in adults; the elderly might have decreased clearance and an increased half-life of 21 hr.
Adverse Reactions.
Patients do not show complete crosstolerance between triazolobenzodiazepines and other benzodiazepines, but clonazepam has been shown to be an effective long-half-life substitute drug for use in alprazolam withdrawal
