Am J Psychiatry 1993; 150:1210-1215
Copyright © 1993 by American Psychiatric Association
Double-blind, placebo-controlled study of a once-a-day, sustained- release preparation of alprazolam for the treatment of panic disorder
E Schweizer, W Patterson, K Rickels and M Rosenthal
Department of Psychiatry, University of Pennsylvania, Philadelphia 19104-2649.
OBJECTIVE: The goals of this study were to assess the antipanic efficacy of
a new, sustained-release formulation of alprazolam and to assess the safety
and tolerability of once-a-day administration of 1-10 mg of
sustained-release alprazolam. METHOD: One hundred ninety-four patients with
diagnosis of agoraphobia with panic attacks or panic disorder with limited
phobic avoidance underwent a 1-week placebo washout before being randomly
assigned to groups receiving 8 weeks of double-blind treatment with either
sustained-release alprazolam or placebo. RESULTS: There was a significant
treatment effect favoring sustained-release alprazolam (highest mean dose =
4.7 mg/day) across almost all measures of anxiety, panic, and phobic
avoidance, despite a significantly higher dropout rate in patients
receiving placebo. Eighty- five percent of the patients treated with
sustained-release alprazolam, compared with 61% of the patients given
placebo, reported complete blockade of panic attacks by the end of 6 weeks
of treatment. Sedation was the most commonly reported adverse effect.
Discontinuation of sustained-release alprazolam was associated with
moderate but transient levels of distress in 48% of the patients;
discontinuation of placebo led to distress in only 10% of the patients.
Nonetheless, there was no difference in the proportion of patients who were
able to remain off the study drug for at least 2 weeks. CONCLUSIONS: These
results suggest that sustained-release alprazolam is highly effective in
the acute treatment of panic disorder at doses comparable to those in the
originally marketed compressed tablet of alprazolam. The medication was
well tolerated but showed rebound effects during a rapid drug taper after 6
weeks of treatment.
