A Double-Blind, Placebo-Controlled Trial of the Safety and Efficacy of Selegiline Transdermal System Without Dietary Restrictions in Patients With Major Depressive Disorder

Background: The monoamine oxidase (MAO) inhibitor selegiline has demonstrated antidepressant efficacy superior to placebo. A selegiline transdermal system (STS) has been developed with unique pharmacokinetic and pharmacodynamic properties that allow inhibition of central nervous system MAO-A and MAO-B enzymes while substantially avoiding inhibition of intestinal and liver MAO-A enzyme. This novel transdermal system provides targeted MAO inhibition without clinically significant increases in sensitivity to dietary tyramine. We investigated the safety and efficacy of STS in patients with major depressive disorder.

Method: 365 outpatients 18 to 65 years old with a DSM-IV diagnosis of major depressive disorder were enrolled at 16 sites. A 17-item Hamilton Rating Scale for Depression (HAM-D-17) score of >=20 was required for entry. Patients were randomly assigned to receive either STS, 20 mg/20 cm², daily or placebo patch for up to 8 weeks. A tyramine-restricted diet was neither required nor advised. Efficacy, safety, and vital sign measures were obtained regularly.

Results: 289 patients were randomly assigned to treatment and received at least 1 on-therapy evaluation (STS, N = 145; placebo, N = 144). Although the effect size was modest, at endpoint, STS was statistically superior to placebo on the MADRS (p = .001) and HAM-D-28 ( p = .039) ratings and showed a nonsignificant superiority on the HAM-D-17 (p = .069) and Clinical Global Impressions-Severity ratings (p < .055). Side effect profiles were similar for STS and placebo with the exception of application-site reaction, which was observed in 31.5% of STS patients and 15.1% of placebo-treated patients (p = .001). No significant differences were observed in blood pressure measures between treatment groups.

Conclusion: Results from this double-blind, placebo-controlled clinical trial demonstrate that STS may have a modest, but statistically significant, antidepressant benefit compared with placebo and a similar safety profile compared with placebo in the absence of a tyramine-restricted diet.