opicapone + warfarin

This is a combination of **opicapone**, a catechol-O-methyltransferase (COMT) inhibitor, and **warfarin**, a vitamin K antagonist anticoagulant. Opicapone is used primarily as adjunctive therapy to levodopa/DOPA decarboxylase inhibitor in Parkinson’s disease to inhibit peripheral COMT and thus increase plasma levodopa levels, improving symptom control[2][4][5]. Warfarin is mainly used for preventing or treating thromboembolic disorders by inhibiting vitamin K-dependent clotting factors via CYP-mediated metabolism. Co-administration studies show that opicapone has minimal effect on warfarin pharmacodynamics (i.e., INR–no clinically relevant changes), with a slight reduction in S-warfarin and R-warfarin AUC and no effect on Cmax[3][5][6]. There is no evidence that this specific combination is marketed as a single product or clinically indicated together, but both drugs are approved for their respective indications.