Efficacy of istradefylline, an A2A receptor antagonist, when added to levodopa and other medications for Parkinson's disease (PD). (October 2020) - Le Witt, P.; Hattori, N.; Mori, A.; Toyama, K.; Salzman, P.M.; Parno, J.; Ristuccia, R.; Isaacson, S.H.