Selective MAO-B inhibitor (oral and transdermal formulations)
Selectively inhibits monoamine oxidase B (MAO-B) at lower doses, increasing synaptic dopamine; at higher doses, non-selective MAO inhibition may occur, increasing monoamines including serotonin and norepinephrine.
Parkinson’s disease (PD) — oral formulation; major depressive disorder (MDD) — transdermal patch (Emsam)
Cognitive and behavioral symptoms in Parkinson’s disease (PD), apathy in dementia, depression in PD, treatment-resistant depression
Oral tablets (5 mg, 10 mg), transdermal patch (6 mg/24h, titratable to 9 mg/24h or 12 mg/24h)
Patch starting dose 6 mg/24h, titratable to 9 or 12 mg/24h; oral dosing varies per indication
Patch 6–12 mg/24h
Transdermal delivery bypasses first-pass gastrointestinal metabolism, allowing selective MAO-B inhibition at lower doses
Insomnia, nausea, dizziness, headache
Hypertensive crisis with tyramine-rich foods at higher doses (non-selective MAOI effect), serotonin syndrome risk with serotonergic agents
Monitor blood pressure, dietary tyramine intake, signs of serotonin syndrome especially when combined with serotonergic drugs
None specific, but caution advised due to MAOI effects and serotonin syndrome risk
The transdermal patch formulation may benefit depressive symptoms with prominent apathy or cognitive slowing, particularly in Parkinson’s disease (PD) or vascular depression. Minimal anticholinergic or sedating effects make selegiline relatively well tolerated in older adults. Use caution when combining with serotonergic agents due to risk of serotonin syndrome, especially at higher patch doses.