I undersøgelse II blev patienterne randomiseret til behandling i 18 uger med enten placebo (229 patienter) eller rasagilin 1 mg dagligt (231 patienter) eller til behandling med 200 mg entakapon, en katekol- O- metyltransferase (COMT) hæmmer (227 patienter), i kombination med levodopa (LD) / decarboxylasehæmmer.
In study II patients were randomly assigned to receive placebo (229 patients), or rasagiline 1 mg/ day (231 patients) or the catechol-O– methyl transferase (COMT) inhibitor, entacapone, 200 mg taken along with scheduled doses of levodopa (LD)/ decarboxylase inhibitor (227 patients), and were treated for 18 weeks.