1. Elevated INR in a COVID‐19 patient after concomitant administration of favipiravir and warfarin: A case report
- Author
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Toru Imai, Nobutaka Chiba, Atsushi Sakurai, Norikazu Kikuchi, Shinji Hidaka, Masao Sekimoto, and Mitsumasa Hata
- Subjects
Drug ,medicine.medical_specialty ,2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,cytochrome P‐450 (CYP) ,Deep vein ,media_common.quotation_subject ,coronavirus disease of 2019 (COVID‐19) ,Case Report ,Favipiravir ,favipiravir ,Gastroenterology ,Internal medicine ,medicine ,Pharmacology (medical) ,heterocyclic compounds ,international normalized ratio (INR) ,cardiovascular diseases ,media_common ,drug‐drug interactions (DDIs) ,Pharmacology ,business.industry ,Warfarin ,medicine.disease ,Thrombosis ,warfarin ,medicine.anatomical_structure ,Concomitant ,business ,medicine.drug - Abstract
What is known and objective Favipiravir is a promising treatment candidate for managing coronavirus disease 2019 (COVID‐19). Warfarin has many drug interactions, but no interactions with favipiravir have been reported. Case summary Our patient was taking warfarin for deep vein thrombosis. The international normalized ratio (INR) was stable (1.65 to 2.0); however, it increased to 4.63 after administering favipiravir. The patient had no other factors justifying this change. What is new and conclusion Favipiravir and warfarin might have previously unidentified drug interactions that elevated the INR. Therefore, INR must be closely monitored when they are concomitantly administered in COVID‐19 patients., It is important to evaluate the drug–drug interactions between the limited antiviral drugs used in COVID‐19 and the drugs used to manage common comorbidities. We report a case of elevated anticoagulant action i.e., international normalized ratio (INR), when favipiravir and warfarin were used concomitantly in a patient with COVID‐19.
- Published
- 2021