Efficacy studies of alprazolam in panic disorder

Alprazolam was the first pharmacological agent to be approved for the treatment of panic disorder. In seeking that approval, the Upjohn Company conducted the earliest large, multicenter drug trials in panic disorder, involving nearly 1,700 patients in 14 countries. The administrative and quality assurance procedures developed for those studies have become a model for subsequent research. Despite this history, the efficacy of alprazolam for panic disorder has been contested. This article summarizes the published multicenter data from the perspective of the assessment criteria recommended by Shear and Maser (1994) and presents comparative findings from the Philadelphia maintenance study and the London/Toronto study of alprazolam and exposure therapy. Data on relapse following treatment discontinuation are also reviewed.