A comparative study of suriclone, lorazepam and placebo in anxiety disorder

In a four-week double-blind randomized trial preceded by a one-week single-blind placebo treatment, the efficacy and the side-effects of suriclone (1.50-2.25 mg/d) (n = 24), lorazepam (5.0-7.5 mg/d) (n = 19) and placebo (n = 21) were compared in 64 outpatients with a DSM-III diagnosis of generalized anxiety disorder (n = 56) or panic disorder (n = 8). Efficacy was measured weekly by means of a global clinical impression scale, the Hamilton Anxiety Rating Scale, the Zung Anxiety Self-Assessment Scale and a target symptom scale. Side-effects were evaluated weekly by an adverse events scale, which recorded the spontaneous complaints and the complaints elicited by an extensive somatic inventory questionnaire. The three groups showed a statistically significant and clinically relevant improvement early on in the treatment: this improvement was maintained during the remaining period. Early on in the treatment there was some indication of a better response, but also of more side-effects, in the suriclone and the lorazepam groups. After four weeks of treatment no difference was found between the three groups either in efficacy or in side-effects. The effect size achieved in the placebo group was not inferior to that of benzodiazepines in general.