Rivaroxaban

Rivaroxaban is an oral anticoagulant that directly inhibits factor Xa, a key enzyme in the coagulation cascade. It is classified as a direct oral anticoagulant (DOAC) and is used to reduce the risk of stroke in nonvalvular atrial fibrillation, to treat and prevent venous thromboembolism (deep vein thrombosis and pulmonary embolism), and to prevent DVT after hip or knee joint replacement.

Mechanism and properties: By selectively inhibiting factor Xa, rivaroxaban decreases thrombin generation and clot formation. It does not require routine coagulation monitoring, but its effect can be influenced by renal and hepatic function and by drug interactions.

Administration and dosing: Rivaroxaban is taken orally and absorption is enhanced by food for higher doses. In nonvalvular atrial fibrillation, the usual dose is 20 mg once daily with the evening meal; a 15 mg once-daily dose is used when creatinine clearance is 15-50 mL/min. For treatment of DVT or PE, the regimen is 15 mg twice daily for 21 days, then 20 mg once daily. For prophylaxis after hip replacement, 10 mg once daily starting 6-10 hours after surgery is used for 35 days; after knee replacement, a 12-day course is typical. Dose adjustments may be needed for renal impairment or drug interactions.

Pharmacokinetics and interactions: Rivoraxaban is metabolized by CYP3A4 and CYP2J2 and is a substrate of P-glycoprotein. Concomitant strong inhibitors or inducers of these systems can alter bleeding risk. Caution is advised in hepatic impairment, significant renal impairment, pregnancy, and in settings involving neuraxial anesthesia due to risk of spinal/epidural hematoma.

Reversal and safety: A specific reversal agent, andexanet alfa, is available in some regions. In other circumstances, non-specific reversal strategies such as prothrombin complex concentrates may be used. Common adverse effects include bleeding and, less frequently, anemia or liver enzyme elevations.