-Case Reports-

A Drug Interaction between Crizotinib and Warfarin in Non-Small-Cell Lung Cancer: A Case Report

Yu Kubomura¹, Yuya Ise¹, Tetsuya Wako¹, Shirou Katayama¹, Rintaro Noro² and Kaoru Kubota²

¹Section of Pharmaceutical Services, Nippon Medical School Hospital, Tokyo, Japan
²Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan

We report a case of increased prothrombin time-international normalized ratio (PT-INR) when crizotinib and warfarin were co-administered. A 74-year-old Japanese woman presented to the hospital with dyspnea, and was diagnosed with anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC). Three years after surgical resection of the tumor, the patient started crizotinib because of the recurrence of NSCLC. She received 2 mg/day warfarin due to a medical history of cerebral infarction and chronic atrial fibrillation. Before crizotinib initiation, the patient's PT-INR was 2.60. After 7 days of daily doses of crizotinib, the patient's PT-INR increased to 3.65. This case report provides the first evidence of a drug interaction between crizotinib and warfarin.

J Nippon Med Sch 2017; 84: 291-293

Keywords
crizotinib, warfarin, drug interaction, prothrombin time-international normalized ratio (PT-INR), non-small-cell lung cancer (NSCLC)

Correspondence to
Yuya Ise, PhD, Section of Pharmaceutical Services, Nippon Medical School Hospital, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
yuyaise@nms.ac.jp

Received, August 14, 2017
Accepted, August 23, 2017