Opipramol for the Treatment of Generalized Anxiety Disorder: A Placebo-Controlled Trial Including an Alprazolam-Treated Group

Abstract

Opipramol, a drug widely prescribed in Germany, is a tricyclic compound with no reuptake-inhibiting properties. However, it has pronounced D2-, 5-HT2-, and H1-blocking potential and high affinity to sigma receptors (sigma-1 and sigma-2). In early controlled trials, anxiolytic effects were revealed. However, those studies were performed before the concept of generalized anxiety disorder (GAD) was established. Because of the interesting receptor-binding profile and promising results of the early clinical trials, the authors performed a state-of-the-art placebo-controlled trial using alprazolam as an active control. Three hundred seven outpatients with GAD were included. After a 7-day single-blind placebo washout, patients were randomly assigned to receive either opipramol (final dose, 200 mg/day), alprazolam (2 mg/day), or placebo and were treated for 28 days. The efficacy of both active compounds was higher than the effects with placebo treatment. There were statistically significant differences (p