Retrospective Study of Selegiline-Antidepressant Drug Interactions and a Review of the Literature

Abstract Selegiline is a selective monoamine oxidase inhibitor used in the treatment of Parkinson's disease. It is estimated that approximately one-half of Parkinsonian patients will develop depression requiring antidepressant drug treatment. Recently, selegiline's package insert was revised to reflect the potential risk of adverse effects when it is used in combination with selective serotonin reuptake inhibitors and tricyclic antidepressants. The objective of our study is to assess the safety of combining selegiline with antidepressants. A retrospective chart review was performed on all 28 patients with Parkinson's disease receiving selegiline and antidepressants concurrently to identify possible drug interactions. Compliance was assessed according to prescription refill records. Suspected adverse reactions with combination therapy were documented. There was a total of 40 selegiline-antidepressant drug combinations involving tricyclic antidepressants (n=25), selective serotonin reuptake inhibitors (n=7), trazodone (n=5), and bupropion (n=3). One patient receiving fluoxetine developed a reaction consistent with the serotonin syndrome; however, it was never documented as such. No other selegiline drug interactions were found. Adverse effects noted were typical of antidepressant monotherapy. Although no selegiline drug interactions were documented in our study, the concurrent administration of selegiline and selective serotonin reuptake inhibitors should be avoided because of literature-reported interactions. We believe that bupropion, tricyclic antidepressants, and trazodone are reasonable choices in combination with selegiline, although tricyclic antidepressants and trazodone may be reserved as second-line treatments.