Drug for inhibiting vascular intimal hyperplasia

摘要

An intimal hyperplasia inhibitor containing a 3(2H)-pyridazinone compound represented by the formula (I): [wherein each of R¹, R² and R³ is independently a hydrogen atom or a C_1-6 alkyl group, X is a halogen atom, cyano or a hydrogen atom, Y is a halogen atom, trifluoromethyl or a hydrogen atom, and A is a C_1-8 alkylene which may be substituted with a hydroxyl group] or a pharmacologically acceptable salt thereof.