BACKGROUND: Despite the literature indicating adverse interactions between warfarin and cytotoxic agents, whether such an interaction occurs when warfarin and gefitinib are used concomitantly is unknown. We analyzed the prevalence of the concomitant use of warfarin and gefitinib, and the incidence of prothrombin time-international normalized ratio (PT-INR) alterations or adverse interactions in concomitant users of warfarin and gefitinib. METHODS: We conducted a retrospective study of patients with non-small cell lung cancer treated at the Kitasato University Hospital who received concomitant warfarin and gefitinib between September 2002 and January 2007. Medical information, including the indication for warfarin use, warfarin dosing and dosing changes, and exposure to gefitinib were collected from computerized databases and medical records. RESULTS: Twelve (4.1%) of 296 patients treated with gefitinib received warfarin. PT-INR elevation occurred in 6 patients (50.0%). Two (16.7%) of the 12 patients had liver metastases. Liver dysfunction was associated with PT-INR elevation (P = 0.0100). CONCLUSION: As there is a possibility of PT-INR abnormalities occurring during the concomitant use of gefitinib and warfarin, clinicians should be aware of this interaction. Because of the potentially severe consequences of this interaction, close monitoring of PT-INR and warfarin dose adjustment are recommended for patients receiving warfarin and gefitinib, especially during the first 2 weeks in the beginning of warfarin therapy.
BACKGROUND: Despite the literature indicating adverse interactions between warfarin and cytotoxic agents, whether such an interaction occurs when warfarin and gefitinib are used concomitantly is unknown. We analyzed the prevalence of the concomitant use of warfarin and gefitinib, and the incidence of prothrombin time-international normalized ratio (PT-INR) alterations or adverse interactions in concomitant users of warfarin and gefitinib. METHODS: We conducted a retrospective study of patients with non-small cell lung cancer treated at the Kitasato University Hospital who received concomitant warfarin and gefitinib between September 2002 and January 2007. Medical information, including the indication for warfarin use, warfarin dosing and dosing changes, and exposure to gefitinib were collected from computerized databases and medical records. RESULTS: Twelve (4.1%) of 296 patients treated with gefitinib received warfarin. PT-INR elevation occurred in 6 patients (50.0%). Two (16.7%) of the 12 patients had liver metastases. Liver dysfunction was associated with PT-INR elevation (P = 0.0100). CONCLUSION: As there is a possibility of PT-INR abnormalities occurring during the concomitant use of gefitinib and warfarin, clinicians should be aware of this interaction. Because of the potentially severe consequences of this interaction, close monitoring of PT-INR and warfarin dose adjustment are recommended for patients receiving warfarin and gefitinib, especially during the first 2 weeks in the beginning of warfarin therapy.
Authors: Nick Thatcher; Alex Chang; Purvish Parikh; José Rodrigues Pereira; Tudor Ciuleanu; Joachim von Pawel; Sumitra Thongprasert; Eng Huat Tan; Kristine Pemberton; Venice Archer; Kevin Carroll Journal: Lancet Date: 2005 Oct 29-Nov 4 Impact factor: 79.321
Authors: Martin H Cohen; Grant A Williams; Rajeshwari Sridhara; Gang Chen; W David McGuinn; David Morse; Sophia Abraham; Atiqur Rahman; Chenyi Liang; Richard Lostritto; Amy Baird; Richard Pazdur Journal: Clin Cancer Res Date: 2004-02-15 Impact factor: 12.531
Authors: Mark G Kris; Ronald B Natale; Roy S Herbst; Thomas J Lynch; Diane Prager; Chandra P Belani; Joan H Schiller; Karen Kelly; Harris Spiridonidis; Alan Sandler; Kathy S Albain; David Cella; Michael K Wolf; Steven D Averbuch; Judith J Ochs; Andrea C Kay Journal: JAMA Date: 2003-10-22 Impact factor: 56.272
Authors: I García Escobar; M Antonio Rebollo; S García Adrián; A Rodríguez-Garzotto; A Muñoz Martín Journal: Clin Transl Oncol Date: 2016-05-04 Impact factor: 3.405