Case Report
Volume: 5 | Issue: 4 | Published: Apr 06, 2021 | Pages: 106 - 108 | DOI: 10.24911/ejmcr/173-1574370156
You cannot always warfawin: a case of significant INR fluctuation with brand to generic conversion of warfarin
Authors: Christopher G. Nixon , Taylor D. Steuber
Article Info
Authors
Christopher G. Nixon
Huntsville Hospital, Huntsville, AL
Taylor D. Steuber
Auburn University Harrison School of Pharmacy, Huntsville, AL.
Publication History
Received: December 16, 2019
Revised: February 24, 2021
Accepted: March 18, 2021
Published: April 06, 2021
Abstract
Background: Warfarin is affected by many variables such as diet, alcohol, and medications; however, it is unclear if brand to generic conversion may also play a role. This case reports a patient with fluctuating international normalized ratio (INR) while being switched from brand to generic temporarily. Case Presentation: A 60-year-old obese white male taking brand name Jantoven© (warfarin) at home for 9 years at a consistent dose for atrial fibrillation was in hospital for treatment of cellulitis. He was switched to generic warfarin at his home dose on admission. While in hospital, he required dose escalation to three times his home dose to achieve a therapeutic INR. Conclusion: Generic warfarin may have different effects on INR when compared to brand name Jantoven©. More research is warranted to determine if differences may truly exist and potential ways to address the issue. Until then, providers should be cognizant of interchanging the two products to monitor for INR variation.
Keywords: Jantoven, warfarin, inpatient, atrial fibrillation, substitution, INR, green
