In vitro studies showed that rasagiline at a concentration of 1 µg/ ml (equivalent to a level that is 160 times the average Cmax ~ 5.9-8.5 ng/ ml in Parkinson’ s disease patients after 1 mg rasagiline multiple dosing), did not inhibit cytochrome P450 isoenzymes, CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP4A.