Competitive inhibitor of poly (ADP-ribose)polymerase (PARP). Prepn: M. J. Suto et al., EP 355720; eidem, US 5177075 (1990, 1993 both to Warner-Lambert). Use and effects as inhibitior: M. J. L. Eliasson et al., Nat. Med. 3, 1089 (1997); K. Takahashi et al., Brain Res. 829, 46 (1999).