Abstract
A 59 years old man who had been given administrating Tranilast for 15 weeks visited our urology clinic complaining of bladder irritability. He previously had PICA treatment for his coronary triple branch disease and began taking Tranilast 600mg per day for the prevention of restenosis. Cystoscopy revealed extensive mucosal edema which strongly suggested an existence of drug induced cystitis. The patient stopped taking Tranilast and the symptom disappeared within 3 weeks. Bladder irrita-bility is a common side effect of Tranilast and it is well known to urologists and pharmacists, however, cardiologists who are responsible for its prescription often recognize it poorly. It is important for pharmacists to inform the side effects of Tranilast to cardiologists and prevent an irresponsible prescription
