[A case of heparin-induced thrombocytopenia after transurethral resection of prostate during anticoagulant therapy].

A 66-year-old man had been receiving anticoagulant therapy for myocardial infarction with warfarin potassium (abbreviated as warfarin) 2 mg/day. Though he had been treated with tamsulosin hydrochloride 0.2 mg/day as diagnosis of benign prostatic hyperplasia, he experienced severe dysuria and wanted to undergo transurethral resection of the prostate. We decided to continue anticoagulant therapy because cardiologist judged that intermission of anticoagulant therapy could cause myocardial infarction. Warfarin 2 mg/day p.o. was replaced with heparin sodium (abbreviated as heparin) 5000 u x 2/day s.c. 6 days prior to surgery, and anticoagulant therapy was stopped on the day of surgery, but resumed on the following day. Purpura appeared around the extremities 18 days after the surgery. Although coagulation testing was normal, platelet counts had markedly been reduced (2,000/mm3). Platelet counts recovered to a level of 228,000/mm3 13 days after cessation of heparin. No other adverse effects were observed. Heparin-induced thrombocytopenia (abbreviated as HIT) was diagnosed clinically. We consider monitoring of platelets to be necessary because an increasing number of patients are on anticoagulant therapy in Japan, and accordingly, the use of heparin is likely to be increased.