Tablets: 10 mg, 15 mg, 20 mg
For reduction in risk of stroke in nonvalvular atrial fibrillation: 20 mg once daily with the evening meal. In patients with impaired renal function (CrCl 15-50 mL/min), give 15 mg once daily with the evening meal.
For the treatment of deep vein thrombosis (DVT) and of pulmonary embolism (PE): 15 mg twice daily with food for 21 days followed by 20 mg once daily with food.
For reduction in the risk of recurrence of DVT and of PE: 20 mg once daily with food.
For prophylaxis of DVT following hip replacement surgery: 10 mg once daily for 35 days.
For prophylaxis of DVT following knee replacement surgery: 10 mg once daily for 12 days.
Pharmacology/Pharmacokinetics:
Rivaroxaban is a selective inhibitor of Factor Xa (FXa). It does not have a direct effect on platelet aggregation but indirectly affects platelet aggregation induced by thrombin. Inhibition of FXa reduces thrombin formation. Oral bioavailability is dose-dependent with lower doses unaffected by food and higher doses increased when taken with food. Peak plasma levels are reached 2-4 hours after administration. Peak protein binding is between 92-95%. Metabolism occurs via oxidation and hydrolysis and excretion occurs via urine and feces. One-third of an absorbed dose is excreted as unchanged drug in the urine. Terminal elimination half-life is between 5-9 hours.
Drug Interactions:
Effects are decreased by strong CYP3A4 inducers (RIFAMPIN, PHENYTOIN, ST. JOHN’S WORT, CARBAMAZEPINE). Effects are increased by combined P-gp and strong CYP3A4 inhibitors (KETOCONAZOLE, RITONAVIR, CLARITHROMYCIN). Increased exposure to rivaroxaban may occur in patients with renal impairment and coadministration with combined P-gp and moderate CYP3A4 inhibitors (erythromycin, diltiazem, verapamil, dronedarone). Additive effects are seen with administered with enoxaparin and warfarin. Bleeding risks increase when used with aspirin, clopidogrel, and NSAIDs.
Contraindications/Precautions:
Contraindicated in patients with active pathological bleeding and in patients with severe hypersensitive reactions to rivaroxaban. Premature discontinuations increase the risk of thrombotic events. Use increases the risk of bleeding. Promptly report any signs of bleeding. PREMATURE DISCONTINUATION OF THERAPY INCREASES THE RISK OF THROMBOTIC EVENTS. MAY CAUSE SPINAL or EPIDURAL HEMATOMA in patients who are receiving neuraxial anesthesia or undergoing spinal puncture. Stop use at least 18 hours before removing an epidural catheter and do not start therapy within 6 hours after removal. Use with caution and adjust dose in patients with renal impairment. Use with caution in patients with severe hepatic impairment.
Adverse Effects:
The most common adverse effect is bleeding events.
Take 15 mg and 20 mg doses with food.
Do not stop therapy without physician approval.
If a dose is missed, take it as soon as possible on the same day then continue with regular dosing schedule.
Do not take this medication with OTC aspirin or anti-inflammatory medications.
Promptly report signs of bleeding to your physician (nose bleeds, bleeding gums, vaginal bleeding, red or dark urine, red or black stools, coughing blood, red or “coffee ground” vomit, headaches, dizziness, or pain and swelling at wound sites).
