ABSTRACT
A 74-year-old female patient with bladder cancer presented with edema in the right lower limb in a follow-up at the outpatient department.She was diagnosed with deep vein thrombosis in the right lower limb, and warfarin treatment was started.Subsequent gemcitabine and cisplatin combination(GC)therapy for prevention of bladder cancer recurrence prolonged the PT-INR to an immeasurable level on day 6 of therapy.Thus, warfarin was immediately discontinued and a single dose of menatetrenone was administered.Subsequently, the PT-INR recovered to 1.36 one day after discontinuation of warfarin.In the second course of GC therapy, warfarin was discontinued before administration of the anticancer drugs, and there was no change in the PT-INR.The abnormally high PT-INR observed in the early stage after GC therapy in this case shows that it is important to monitor blood coagulation from immediately after administration of GC therapy in a patient under treatment with warfarin.
