A double blind comparison of zimelidine and amitriptyline in endogenous depression

In a randomized double-blind group comparison study of 40 patients with endogenous depression zimelidine appeared to be as effective an antidepressant as amitriptyline at 4 and 6 weeks using the Hamilton Rating Scale (HRS) and the Montgomery and Asberg Depression Rating Scale (MADRS). At 2 weeks there was a significantly better response (P less than 0.05) on zimelidine compared to amitriptyline on the clinician's global scale and 4 out of 10 items on the MADRS suggesting an early onset of action. A significant better response to zimelidine was seen on the item somatic anxiety (HRS) while the effect on sleep and appetite was better in the amitriptyline group. There were significantly more side effects, raw and corrected, in the amitriptyline-treated group. High steady state plasma concentrations of norzimelidine (greater than 800 nmol/l) which were significantly correlated with age (r = 0.8) were associated with a significantly poorer response suggesting that a lower dose than 200 mg in older patients may be appropriate.