Selegiline
Emsam · Eldepryl
Monoamine Oxidase Inhibitor (MAO-B selective at low doses)Generic available
Clinical Pharmacology The mechanisms accounting for selegiline's beneficial adjunctive action in the treatment of Parkinson's disease are not fully understood. Inhibition of monoamine oxidase, type B, activity is generally considered to be of primary importance; in addition, there is evidence that selegiline may act through other mechanisms to increase dopaminergic activity. Selegiline is best known as an irreversible inhibitor of monoamine oxidase (MAO), an intracellular enzyme associated with the outer membrane of mitochondria.
Compare Selegiline →FDA-Approved Indications
- Parkinson's disease — adjunct to levodopa/carbidopa (adults)
Common Off-Label Uses
- ADHD
- Alzheimer's disease (adjunct)
What Sets This Drug Apart
- Two distinct clinical identities: oral low-dose (Eldepryl 5-10 mg) is MAO-B selective for Parkinson's; transdermal patch (EMSAM) is non-selective MAOI for MDD
- EMSAM 6 mg/24h patch does NOT require tyramine dietary restrictions — unique among MAOIs and a critical advantage for compliance
- At EMSAM doses above 6 mg/24h (9 mg, 12 mg), dietary restrictions ARE required — dose-dependent selectivity loss
- Weight-favorable profile: mean 1.2 lbs LOSS on EMSAM vs 0.3 lbs GAIN on placebo; minimal sexual dysfunction (<1%)
- Transdermal delivery bypasses first-pass metabolism and GI MAO inhibition, which is why low-dose EMSAM avoids the tyramine 'cheese reaction'
- Active metabolites include l-methamphetamine and l-amphetamine — can cause false-positive amphetamine screens