Efficacy and Tolerability of Tranylcypromine Versus Phenelzine: A Double-Blind Study in Antidepressant-Refractory Depressed Inpatients

Tom K. Birkenhäger, M.D., Ph.D.; Walter W. van den Broek, M.D., Ph.D.;Paul G. Mulder, Ph.D.; Jan A. Bruijn, M.D., Ph.D.; and Peter Moleman, Ph.D.

Background: The aim of this study was to examine whether phenelzine is a suitable alternative to tranylcypromine in antidepressant-resistant depression.

Method: A total of 77 severely depressed inpatients, meeting the DSM-IV criteria for major depressive disorder, who failed to respond to fixed plasma level treatment with either tricyclic antidepressants or fluvoxamine were withdrawn from psychotropic medication and included in a double-blind flexible-dose 5-week comparison of tranylcypromine and phenelzine.

Results: Of the 77 patients, 67 (87%) completed the trial, of whom 35 (52%) responded. No significant differences in response between both drugs were observed. Seventeen (44%) of 39 patients responded to tranylcypromine and 18 (47%) of 38 to phenelzine (>= 50% reduction in Hamilton Rating Scale for Depression [HAM-D] score). The mean reduction in HAM-D score was 10.4 ± 8.3 for the tranylcypromine sample versus 8.3 ± 8.4 for the phenelzine-treated patients. Only a few patients (10%) used concomitant psychotropic medication. A substantial number of patients experienced severe side effects, mainly dizziness, agitation, and insomnia; the incidence was the same in both samples (21%).

Conclusion: No difference in efficacy was observed between both monoamine oxidase inhibitors in a sample of patients with severe antidepressant-refractory depression. Phenelzine appears to be a suitable alternative to tranylcypromine.

(J Clin Psychiatry 2004;65:1505-1510)

Received March 15, 2004; accepted April 26, 2004. From the Departments of Psychiatry (Drs. Birkenhäger, van den Broek, and Bruijn) and Epidemiology and Biostatistics (Dr. Mulder), Erasmus Medical Centre, Rotterdam; and Moleman Psychopharmacology, Amerongen, and the Department of Clinical Psychology, Katholieke Universiteit Nijmegen, Nijmegen (Dr. Moleman), the Netherlands.

This study was supported by an unrestricted grant from Parnassia Psychomedical Center, The Hague, the Netherlands.

C. Verploegh, R.N., and J. Veenhoven, R.N., assisted in study coordination.

Corresponding author and reprints: Tom K. Birkenhäger, M.D., Department of Psychiatry, Erasmus Medical Centre, P.O. Box 2040, 3000 CA Rotterdam, the Netherlands (e-mail: t.birkenhager@erasmusmc.nl).