Long-term comparison of alprazolam, lorazepam and placebo in patients with an anxiety disorder

In a double-blind, placebo-controlled study of 200 patients with moderate to moderately severe anxiety we compared the anxiolytic efficacy and safety of alprazolam and lorazepam. Dosing was flexible and ranged from 1 to 4.5 mg/day of alprazolam and from 2 to 9 mg/day of lorazepam. The mean daily dose at the end of the 16 week study was alprazolam 3.3 mg and lorazepam 5.1 mg. Both active drugs were significantly more effective than placebo in relieving the symptoms of anxiety on the Hamilton Anxiety Rating Scale, with a trend toward more improvement in the alprazolam group in the later weeks of the study. Target Symptoms, Physician's and Patient's Global Impressions and the Self Rating Symptom Scale indicate that alprazolam and lorazepam were superior to placebo. The major side effects were sedation and drowsiness; the frequency was similar for alprazolam and lorazepam and twice as high for active drug as placebo. An overall rating of side effect severity was not significantly different among the three groups.