Selegiline transdermal system in the treatment of depressive disorders

Selegiline is a selective irreversible inhibitor of monoamine oxidase (MAO)-B during lowdose oral treatment. Additional MAO-A inhibition occurs in higher dose ranges. Selegiline transdermal system (STS) shows a more potent MAO inhibition in comparison with orally administered selegiline, and at minimum doses of 20 mg/20 cm(2) patch delivering 6 mg/24 h, no dietary restrictions, including low-tyramine food, are necessary. While oral selegiline has been used for years in the treatment of Parkinson's disease, the US FDA recently approved the STS for use in treating major depression. Data from three randomized controlled trials showed a significantly better efficacy of STS in the treatment of unipolar major depression in comparison with placebo during 6-8 weeks of treatment. In addition, one long-term randomized controlled trial demonstrated the efficacy of the STS in relapse prevention of unipolar depression over 1 year. A total number of 515 depressed patients received STS during these studies. The tolerability profile of STS without dietary restrictions was excellent. The only side effects that were more frequent than with placebo were applicationsite reactions. No change in vital parameters and no hypertensive crisis have been recorded. Comparative studies including treatment with established antidepressants and the investigation of bipolar depressed patients and of specific patient subgroups (e.g., anergic and atypical depression) have to follow. The combination of the well-known effectiveness of irreversible MAO inhibitors with a good tolerability profile and a new pharmaceutical form, possibly enhancing compliance, represents a promising further expansion of the pharmacotherapeutic repertoire in the treatment of depression.