[Patient with warfarin poisoning caused by coumarin rodenticide]

We report a patient who attempted suicide by taking warfarin as a coumarin rodenticide twice, and showed oral bleeding and an abnormally prolonged bleeding tendency after 10 days. He was conscious. His body temperature was 36.6 degrees C, the respiratory rate was 23/min, and blood pressure was 142/87 mmHg. A bite wound showing continuous bleeding was observed on the right side of the oral cavity. CT of the head and upper gastrointestinal endoscopy showed no intracranial and gastrointestinal bleeding,respectively. The PT and INR were extremely high, and complete blood count revealed anemia. Blood chemistry showed hypoproteinemia. Occult blood was strongly positive. Routine urine examination and electrocardiography showed neither abnormal nor characteristic findings. In drug/ poison screening tests, GC/MS analysis revealed warfarin artifacts in serum and urine samples. Warfarin was isolated from each sample, converted to a TMS derivative, and quantified by SIM analysis of GC/MS. During the clinical course, KaytwoN (vitamin K) was intravenously administered at a dose of 20 mg since the INR at the first consultation was 20.89. After admission to the ICU, 20 mg Kaywan (vitamin K) was orally administered, and the INR after 5 hours improved to 2.32. Kaywan administration (20 mg/day) was initiated, and he improved and was discharged 5 days after admission. The definite cause could be clarified by drug/poison analysis, and effective treatment could be performed.