Rivaroxaban, commonly known by the brand name Xarelto, is an anticoagulant medication. It functions as a direct factor Xa inhibitor, blocking a specific substance in the blood clotting cascade, thereby preventing blood clots from forming or growing. This reduces the risk of serious health problems.
Standard Dosages for Different Conditions
Rivaroxaban dosages vary depending on the condition being treated or prevented. For treating deep vein thrombosis (DVT) and pulmonary embolism (PE), the initial dosage is 15 mg twice daily with food for 21 days. The dosage then transitions to 20 mg once daily with food for continued treatment.
For preventing DVT and PE after hip or knee replacement surgery, 10 mg once daily is prescribed. This treatment begins 6 to 10 hours after surgery, once bleeding has stabilized, and continues for 35 days following hip replacement or 10 to 14 days after knee replacement.
To prevent stroke and systemic embolism in patients with non-valvular Atrial Fibrillation (AFib), the dosage is 20 mg once daily with the evening meal. For individuals with reduced kidney function (creatinine clearance between 15 and 49 mL/min), 15 mg once daily with food is prescribed.
To reduce the risk of major cardiovascular events in patients with coronary artery disease (CAD) or peripheral artery disease (PAD), rivaroxaban is given at 2.5 mg twice daily. This is taken in combination with aspirin (75 mg to 100 mg once daily).
Adjusting Rivaroxaban Dosage
Dosage adjustments for rivaroxaban are necessary, particularly in patients with impaired kidney function. Approximately one-third of the rivaroxaban dose is eliminated by the kidneys. A decline in kidney function can lead to increased drug levels, raising the risk of bleeding.
For patients with non-valvular AFib, if kidney function is moderately impaired (creatinine clearance 15-49 mL/min), the dose is reduced from 20 mg to 15 mg once daily. For DVT or PE treatment and prevention, no dose reduction is required for patients with creatinine clearance 15 mL/min or greater, although close observation is recommended for those with creatinine clearance 15-29 mL/min. Rivaroxaban is not recommended for patients with end-stage renal disease or those on dialysis due to limited clinical data.
Liver function plays a role in rivaroxaban’s metabolism. Patients with moderate to severe liver impairment (Child-Pugh B and C) or any liver disease associated with clotting problems are advised to avoid rivaroxaban because of increased drug exposure and bleeding risk.
Drug interactions can impact rivaroxaban’s effectiveness or safety. Certain medications, particularly strong inhibitors of CYP3A4 and P-glycoprotein (P-gp), can increase rivaroxaban levels, leading to a higher bleeding risk. Examples include some antifungal and antiviral medications. Conversely, strong inducers of these enzymes can decrease rivaroxaban levels, reducing its effectiveness.
Practical Dosage Guidance
For optimal absorption, take 15 mg and 20 mg rivaroxaban doses with food. The 10 mg dose can be taken with or without food. Taking the medication consistently at the same time each day maintains stable drug levels.
Missed Dose Guidance
If a rivaroxaban dose is missed, actions depend on the prescribed regimen.
For once-daily doses (10 mg, 15 mg, or 20 mg): Take the missed dose as soon as it is remembered on the same day. Unless it is almost time for the next scheduled dose, in which case skip the missed dose. Never take more than one dose in a single day.
For 15 mg twice-daily doses: Take the missed dose immediately. If it is almost time for the next dose, two 15 mg tablets can be taken together to ensure the total daily dose.
For 2.5 mg twice-daily doses: Take the missed dose as soon as remembered. Unless it’s nearly time for the next, then skip it.
Patients inform all healthcare providers, including dentists, about rivaroxaban use before any medical or dental procedures. For procedures with a high bleeding risk, temporary interruption of rivaroxaban is required. The decision to interrupt and restart the medication is made by a healthcare professional, considering individual bleeding and clotting risks.
Adherence to the prescribed rivaroxaban regimen is important for preventing blood clots. Skipping doses or stopping the medication without consulting a doctor increases the risk of serious events like stroke or recurrent blood clots. Higher adherence rates have been observed with rivaroxaban compared to some other oral anticoagulants, partly due to its once-daily dosing for many indications.