A naturalistic study of imipramine in panic disorder and agoraphobia.

This naturalistic study examined the treatment response to imipramine of 60 patients who had panic disorder or agoraphobia with panic attacks. Only half of the patients could tolerate the drug, but of those who did, 88% obtained a markedly beneficial clinical effect. An amphetamine-like side effect accounted for most of the dropouts. More than one-half of the responders achieved clinical remission at doses (less than or equal to 100 mg/day) and plasma levels (less than or equal to 150 ng/ml) considered to be subtherapeutic for depression. There appears to be neither a clear threshold for response nor a therapeutic dose range for imipramine in the treatment of panic. Doses should be adjusted individually and increased conservatively.