Lactate-induced anxiety after imipramine and diazepam treatment.

To examine the effect of treatment on lactate-induced anxiety in a controlled study, we infused 44 panic disorder patients with lactate and placebo before and after eight weeks of double-blind treatment with imipramine, diazepam, or placebo. During treatment, both imipramine and diazepam groups improved more than the placebo group. After treatment, patients in both the imipramine and diazepam groups had significantly less anxiety than the placebo patients when reinfused with lactate. In addition, imipramine decreased posttreatment panic attack frequency and diazepam decreased the perceived severity of posttreatment lactate-induced panic attacks. This study demonstrates that diazepam, like imipramine, is an effective treatment for panic disorder, and that both imipramine and diazepam blunt lactate-induced anxiety in a placebo controlled study.