Alprazolam premedication and 35% carbon dioxide vulnerability in panic patients.

A group of 20 patients who met the DSM-III-R criteria for panic disorder with or without agoraphobia underwent a 35% carbon dioxide (CO2) challenge after either 1 mg alprazolam or placebo in a double-blind, randomized, cross-over design. Despite the anxiolytic potential of alprazolam, it produced no significant effects on CO2-induced anxiety and panic symptomatology when compared to placebo.