A multicentre double-blind comparative trial of zimeldine and imipramine in primary major depressive disorders

Zimeldine, a new antidepressant with a selective inhibition of 5-HT reuptake, was compared with imipramine in a double-blind comparative study. The trial was conducted on 95 patients with primary major depressive disorder, of endogenous character. During the 4-week study period clinical efficacy was evaluated by using the Hamilton Depression (HAM-D) scale, Beck's Inventory and global ratings. Zimeldine (100 mg b.d.) was shown to have as good an antidepressive effect as imipramine (50 mg t.d.s.) when evaluated on the HAM-D scale. Assessment of the symptom improvement on this rating scale suggested that zimeldine was more effective in improving the patient's insight of the disease. There was no significant difference between zimeldine and imipramine as assessed by a final global improvement rating scale as well as by the patient's own impression. Exploratory data analysis revealed that zimeldine was significantly more effective than imipramine in the following groups; patients over 40 years of age; patients whose initial onset of illness occurred at over 40 years; patients with a history of at least three episodes of depressive illness; patients with mild to moderate depression; and patients who had previously failed to show an appreciable response to other antidepressant treatment. Analysis of global safety ratings revealed that zimeldine is significantly safer than imipramine, with a lower incidence of adverse symptoms involving the autonomic nervous system, especially anticholinergic reactions. No significant difference was observed between the two groups with respect to abnormal laboratory reports. One zimeldine patient developed symptoms suggesting a hypersensitivity reaction (fever, skin eruption and elevation of plasma levels of transaminases), which led to the patient's withdrawal from drug treatment.