Clinical trials of fluvoxamine vs chlorimipramine with single and three times daily dosing

1 Two double-blind, randomised studies were performed to compare the efficacy of fluvoxamine and chlorimipramine in depressed patients. In the first study the effects of a single daily dosage of between 100 and 300 mg of fluvoxamine were compared with those of chlorimipramine at a dosage of 50-150 mg daily in 43 out-patients with endogenous depression. 2 In a second study using three times daily dosing with a daily dosage of 150-300 mg for both fluvoxamine and chlorimipramine, 30 in-patients with unipolar depression were assessed. 3 Four weeks of treatment with single daily dosing resulted in a mean improvement of 61.4% (+/- s.d. 31.7) on the Hamilton Rating Scale for Depression (HAMD) for fluvoxamine and of 65.3% (+/- s.d. 25.8) for chlorimipramine. In the study with three times daily dosing the mean results were 72.9% (+/- s.d. 22.3) improvement for fluvoxamine and 62.1% (+/- s.d. 28.5) for chlorimipramine. 4 At similar dosages, fluvoxamine had significantly less untoward effects on blood pressure than chlorimipramine. Anticholinergic effects were also fewer in the fluvoxamine group, as were nervous system symptoms, with the latter difference reaching statistical significance (P = 0.02). 5 We conclude that fluvoxamine, given in a single daily dose of 150-250 mg, provides antidepressant efficacy similar to chlorimipramine. At this dosage it may be expected to produce less anticholinergic effects and have less influence on blood pressure than chlorimipramine.