title: Evaluation of the anticoagulant effect and timing of the concomitant use of S-1 and warfarin.
abstract: Objectives To evaluate the effects of the timing of warfarin (WF) administration in patients with gastric cancer who received S-1 oral chemotherapy. Methods This retrospective chart review collected patient data including the prothrombin time international normalized ratio (PT-INR). Patients were categorized into three groups based on the timing of WF administration in relation to S-1 oral chemotherapy: group A patients received WF before S-1 chemotherapy; group B patients started WF during S-1 chemotherapy; and group C patients started WF after completing S-1 chemotherapy. Results A total of 21 patients with gastric cancer were included in the study; group A ( n = 8), group B ( n = 10) and group C ( n = 3). Seven patients (88%) in group A, seven (70%) in group B and all of the patients (100%) in group C had >2.5 PT-INR. There was no significant difference in the time-to-exceed 2.5 PT-INR between groups A and B. Conclusions These findings suggest that the timing of WF use in relation to S-1 chemotherapy might not be an important factor for PT-INR, although the low patient numbers included in the study should be taken into consideration.
authors.affiliation: 1 Division of Pharmacy, National Cancer Center Hospital East, Kashiwa, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: 1 Division of Pharmacy, National Cancer Center Hospital East, Kashiwa, Japan.
authors.forename: Kiwako
authors.initials: K
authors.lastname: Ikegawa
authors.affiliation: 1 Division of Pharmacy, National Cancer Center Hospital East, Kashiwa, Japan.|2 Department of Pharmacy, Kobe City Medical Center General Hospital, Kobe, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: 1 Division of Pharmacy, National Cancer Center Hospital East, Kashiwa, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Saito
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000627:therapeutic use*; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000627:therapeutic use*; D004338:Drug Combinations; D004347:Drug Interactions; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D010094:Oxonic Acid / Q000008:administration & dosage* / Q000627:therapeutic use*; D011517:Prothrombin Time; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy*; D005641:Tegafur / Q000008:administration & dosage* / Q000627:therapeutic use*; D014859:Warfarin / Q000008:administration & dosage* / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D000964:Antimetabolites, Antineoplastic; D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D014859:Warfarin; D010094:Oxonic Acid
keywords: S-1; drug interaction; prothrombin time international normalized ratio (PT-INR); warfarin