Elucidating the Mechanism of Action and Potential Interactions of MAO-B Inhibitors

A critical enzyme in neurotransmitter metabolism is monoamine oxidase (MAO). MAO occurs in two isoforms, MAO-A and MAO-B. MAO inhibitors are classified as selective for a particular subtype of MAO or nonselective and can be reversible or irreversible. Nonselective MAO inhibitors originally were studied as antidepressants. Newer MAO-B selective irreversible inhibitors are indicated for use in treatment of Parkinson's disease. MAO-B inhibitors offer modest antiparkinsonian effects, as they do not inhibit brain MAO-A effectively at the dose used in treating Parkinson's disease. In this article, the mechanism of action of MAO-B inhibitors, their potential neuroprotective effects, interactions such as the cheese reaction, and serotonin syndrome are discussed.