ADORA2A and Parkinson disease: KW6002 (istradefylline) is considered the most suitable A2AR antagonist for oral administration in CNS studies, based on its bioavailability, half-life and brain penetration.36 Additionally, KW6002 has undergone a clinical trial for Parkinson’s disease as its safety has been established,37 being approved for the adjunctive treatment of Parkinson’s disease in Japan.38