Double-blind comparative study of the antidepressant, unwanted and cardiac effects of minaprine and amitriptyline.

1. A double-blind, multicentre study comparing the efficacy and safety of minaprine and amitriptyline in patients with major depression was carried out. Five hundred and thirty-one patients were randomly assigned to treatment with either minaprine 100 mg, 200 mg or 300 mg day-1 or with amitriptyline 150 mg day-1 (75 mg during the first week). The medication was administered for 6 weeks. 2. Efficacy was assessed using the Hamilton rating scale for depression (HDRS), the Montgomery-Asberg depression rating scale (MADRS) and visual analogue assessments of depression carried out by both the investigators and patients. Unwanted effects were assessed by a questionnaire and spontaneous reporting. In a subgroup of patients cardiovascular effects were investigated by high speed ECG and systolic time intervals. 3. Patients in each treatment group showed a significant clinical improvement (P < 0.01) from baseline. The mean HDRS and MADRS scores adjusted for baseline differences, showed significantly less improvement in the minaprine 100 mg once daily (P < 0.01) and the minaprine 300 mg daily (P < 0.01) groups than in the amitriptyline group at both week 4 and week 6. The MADRS score at week 4 suggested that 200 mg day-1 minaprine was less effective than amitriptyline (P < 0.05), but there was no difference between the two groups at week 6 on either the HDRS or the MADRS. 4. Both drugs were well tolerated and there were no significant differences between treatment groups in any of the safety and tolerance assessments. In the ECG, amitriptyline produced a significant increase in the heart rate and PR interval while minaprine had no effect on electrocardiographic measurements. Neither drug produced changes in the systolic time intervals.