What rivaroxaban does
Rivaroxaban is a direct oral anticoagulant, or DOAC. It works by blocking Factor Xa — a clotting protein that helps generate thrombin. With less thrombin around, clots are less likely to grow or form in the first place. The effect starts within a few hours of a dose and lasts roughly 24 hours, which is why we can dose it once a day in most situations.
Rivaroxaban is sold in the United States as Xarelto (rivaroxaban) by Janssen (a Johnson & Johnson company), with Bayer as its global co-developer.
Who we prescribe it for
The most common reasons we start rivaroxaban are:
- Stroke prevention in atrial fibrillation — based on your individual stroke risk score.
- Treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE).
- Prevention of recurrent venous clots at a reduced dose.
- Post-orthopedic surgery clot prevention after hip or knee replacement.
- Stable cardiovascular disease — a very low dose paired with aspirin is occasionally used for patients with coronary or peripheral artery disease, though we typically defer that to the patient’s cardiologist.
We do not use rivaroxaban in patients with mechanical heart valves or rheumatic mitral stenosis — warfarin is required in those settings.
How to take it
For atrial fibrillation:
- 20 mg once daily with the evening meal is the standard.
- 15 mg once daily with the evening meal if your creatinine clearance is between 15 and 50 mL/min.
The “with food” part matters. At the higher doses, food meaningfully improves absorption — taking it on an empty stomach can leave you under-protected. The lower doses used for clot prevention can be taken with or without food.
For acute DVT or PE treatment, the dose starts higher (15 mg twice daily for the first three weeks), then steps down to 20 mg once daily.
If you miss a dose: take it the same day if you remember within several hours of the usual time. If it’s nearly the next day, skip it and continue normally. Don’t double up.
Side effects to watch for
The main side effect is bleeding, and the patterns are the same as with the other DOACs: minor bruising and slower clotting from small cuts are common; significant bleeding is uncommon but requires prompt attention.
Call us or seek care immediately for:
- Black or tarry stools, or bright red rectal bleeding.
- Vomiting blood or coffee-ground material.
- Sudden severe headache or new neurologic symptoms (weakness, numbness, difficulty speaking, vision change).
- Blood in the urine.
- A fall with a head impact.
Some patients have GI upset, which often improves by taking the dose with a substantial meal rather than a snack.
Drug and food interactions
Rivaroxaban is processed by CYP3A4 and P-glycoprotein. Medications that strongly affect both should generally be avoided:
- Strong inhibitors (raise rivaroxaban levels, more bleeding): ketoconazole, itraconazole, ritonavir, certain HIV medications.
- Strong inducers (lower rivaroxaban levels, less protection): rifampin, phenytoin, carbamazepine, St. John’s wort.
Combining with aspirin, NSAIDs, or another anticoagulant raises bleeding risk and we only do it when there’s a clear reason.
Food itself is not a problem — there are no leafy-greens restrictions like with warfarin. The “take it with food” rule for the AFib dose is about absorption, not interaction.
Around procedures
For most procedures, we hold rivaroxaban for 24 to 48 hours beforehand, longer if kidney function is reduced. For minor dental work, we usually don’t stop it. We’ll give you specific instructions for anything planned.
Reversal in an emergency
Andexanet alfa is a targeted reversal agent that binds rivaroxaban and turns off its effect. Four-factor prothrombin complex concentrate (4F-PCC) is the alternative used in many hospitals. For minor bleeding, holding the next dose is often enough — the drug clears within roughly a day.
When to check in with us
Tell us about any unusual bleeding, falls, changes in kidney function, or upcoming procedures. We monitor kidney function at least yearly — more often if it is reduced or trending down — because the dose depends on it.
Manufacturer reference
For official prescribing information, indications, and the latest information on Xarelto (rivaroxaban) from Janssen / Bayer, see the manufacturer’s site: xarelto-us.com. (External link — content there is the manufacturer’s and may include promotional material.)