rivaroxaban and carbamazepine

Carbamazepine is a potent inducer of cytochrome P450 3A4 (CYP3A4) and the efflux transporter P-glycoprotein (P-gp). Rivaroxaban is a substrate of both CYP3A4 and P-gp. Co-administration leads to increased clearance and reduced systemic exposure of rivaroxaban.

Plasma concentrations of rivaroxaban are significantly decreased, which reduces its anticoagulant effect. This may lead to an increased risk of thromboembolic events such as stroke, deep vein thrombosis, or pulmonary embolism in patients receiving rivaroxaban for prevention or treatment of thrombosis.

Avoid co-administration if possible. If combined therapy is necessary, monitor patients closely for signs of thrombosis and consider alternative anticoagulants that are not affected by CYP3A4/P-gp induction. If rivaroxaban is continued, consider dose adjustment and regular assessment of thromboembolic risk. Consult local guidelines and specialist advice.

The interaction is well established based on pharmacokinetic studies and clinical observations. Carbamazepine is known to reduce rivaroxaban exposure by up to 50% or more. Product information for rivaroxaban lists carbamazepine as an interacting drug that should be avoided. No specific citations are provided.