Minor
Probable
Descrição
Oseltamivir does not appear to meaningfully alter warfarin pharmacokinetics; however, the febrile illness being treated may independently elevate INR, which can be mistakenly attributed to the antiviral.
Mecanismo
Oseltamivir and its active metabolite are eliminated by renal tubular secretion and have no significant effect on CYP2C9; any INR changes are more likely related to reduced vitamin K intake or fever-driven changes in clotting factor catabolism.
Significância Clínica
Pharmacokinetic studies confirm no direct interaction; vigilance is warranted because influenza itself can destabilise anticoagulation.
Conduta
Monitor INR during the acute illness period; adjust warfarin dose based on INR measurements rather than prophylactically.