This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To compare individual active drugs (antidepressants, benzodiazepines and azapirones) and placebo in terms of efficacy and acceptability in the acute treatment of panic disorder, with or without agoraphobia. To rank treatments for panic disorder (antidepressants, benzodiazepines, azapirones and placebo) according to their effectiveness and acceptability.