Generic Name

Rivaroxaban

Brand Names

*Xarelto*) is a *direct oral factor Xa inhibitor* (DOAC) used for prevention and treatment of venous thromboembolism (VTE), atrial fibrillation (AF)-related stroke, and for secondary prevention after acute coronary syndrome (ACS).

Mechanism

• Selective, reversible inhibition of factor Xa—prevents conversion of prothrombin to thrombin.
• Direct oral anticoagulant (DOAC): does not require vitamin K antagonism or routine coagulation monitoring.
• Rapid onset; peak effect within 2–4 h; half‑life of 5–9 h (shorter in the elderly).

Pharmacokinetics

• Absorption: Well absorbed; bioavailability ~ 80 % (decreases ~ 30 % with high‑dose food).
• Peak plasma concentration: 2–4 h post‑dose.
• Distribution: ~ 95 % plasma protein binding (mostly albumin and α_1‑acid glycoprotein).
• Metabolism: Primarily CYP3A4/5, CYP2J2, and UGT1A4/1A1; minor contribution via P‑gp efflux.
• Elimination: ~ 35 % renal, 65 % via hepatic excretion and biliary routes.
• Half‑life: 5 h (young adults) to 9 h (elderly), 1 day for high‑dose (15 mg BID).

Indications

• Treat acute VTE (deep vein thrombosis, pulmonary embolism) and prevent recurrence for 6 months.
• Extended‑duration VTE prophylaxis in hospitalized patients at risk (e.g., hip/knee replacement surgery).
• Prevention of ischemic stroke and systemic embolism in non‑valvular AF (standard dose 20 mg daily; 15 mg BID for CrCl 15–49 mL/min).
• Secondary prevention after ACS (15 mg daily for 12 months, then 7.5 mg daily if indicated).

Contraindications

• Contraindicated:
• Active major bleeding.
• Known hypersensitivity to rivaroxaban or any excipient.
• Severe hepatic impairment (Child‑Pugh C).
• Warnings:
• Bleeding risk: major bleeding, GI haemorrhage, intracranial hemorrhage.
• Use with caution in patients on potent CYP3A4/P‑gp inhibitors (e.g., ketoconazole, ritonavir) or inducers (e.g., rifampicin, carbamazepine).
• Pregnancy: category X; avoid in pregnancy; use in lactation only if benefits outweigh risks.

Dosing

| VTE prophylaxis | 10 mg daily | 10–14 days (post‑op) | Avoid in CrCl 12 h late, skip next scheduled dose.

Adverse Effects

• Common: dyspepsia, nausea, headache, back pain, bruising, urinary tract infection.
• Serious: major or clinically relevant non‑major bleeding, GI ulceration, haemorrhagic stroke, hypersensitivity reactions.
• Monitoring for adverse events: watch for signs of bleeding, bruising, hematuria, and GI pain.

Monitoring

• Routine coagulation tests not required.
• Renal function: CBC; CrCl every 3 months (or sooner if CrCl <50 mL/min).
• Platelet count: baseline and periodically if thrombocytopenia suspected.
• Hemoglobin/hematocrit: baseline and periodically, especially if bleeding symptoms occur.

Clinical Pearls

• Quick reversal: use 4 mg of andexanet alfa for life‑threatening bleeding; activated charcoal if ingestion 50 mL/min for extended therapy.
• Peri‑operative: stop 1 day before low‑bleeding‑risk surgery (if CrCl >30 mL/min); 2 days before high‑bleeding‑risk surgery; resume 24–48 h post‑op once hemostasis secured.
• Pregnancy & lactation: counsel patients; use contraception during therapy; limited data on infant exposure—prefer discontinuation before planned delivery.

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• *For detailed prescribing information, consult the latest *FDA prescribing label* or institutional formulary.*