MAOB and Parkinson disease: Rasagiline is a selective and irreversible monoamine oxidase (MAO) B inhibitor, which is well tolerated, safe, improves motor symptoms, and prevents motor complications in PD.Monoamine oxidases are a family of enzymes that catalyze the oxidation of monoamines.and catalyzes the oxidative deamination of monoamines MAO-B is mostly found in blood platelets.