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.