💊 Rivaroxaban is an oral direct Factor Xa inhibitor.
✅ Indicated in non-rheumatic AF with one or more risk factors: previous stroke/TIA, heart failure, age >75, diabetes, or hypertension.
⚠️ Always check the BNF link here for the latest prescribing guidance.
📖 About
- Alternative to warfarin for stroke prevention in non-valvular AF.
- Also used in DVT, PE, and post-operative VTE prophylaxis.
- Convenient fixed dosing, no INR monitoring required.
- Cost: ~£3/day in the UK 💷.
⚙️ Mechanism of Action
- Factor Xa normally converts prothrombin → thrombin → fibrin clot.
- Rivaroxaban directly inhibits Factor Xa (both free and clot-bound in the prothrombinase complex).
- Half-life ~12 hours, with ~66% renal excretion → dose adjustments needed in renal impairment.
📌 Indications & Doses
- Non-valvular AF:
- CrCl >50 mL/min → 20 mg PO OD with evening meal.
- CrCl 15–50 mL/min → 15 mg PO OD with evening meal.
- VTE prophylaxis:
- Knee replacement → 10 mg OD for 2 weeks (start 6–10h post-op).
- Hip replacement → 10 mg OD for 5 weeks (start 6–10h post-op).
- DVT/PE treatment:
- 15 mg BD for 21 days, then 20 mg OD with food.
- Some may continue 15 mg OD for extended prevention.
- ACS (adjunct): 2.5 mg BD, usually for 12 months.
🔄 Interactions
- ↑ Bleeding risk with: Aspirin, P2Y12 inhibitors (clopidogrel, ticagrelor), other anticoagulants, fibrinolytics, NSAIDs.
- Avoid with CYP3A4 inducers: Carbamazepine, Phenytoin, Rifampicin, St. John’s wort.
- Avoid with CYP3A4 inhibitors: Ketoconazole, Ritonavir, Clarithromycin, Erythromycin, Fluconazole.
⚠️ Cautions
- Renal impairment (dose-adjust or avoid if severe).
- Liver disease with coagulopathy.
- High falls risk → weigh up bleeding vs stroke risk.
⛔ Contraindications
- Active pathological bleeding.
- Recent major surgery (brain, spine, ophthalmic).
- Recent intracranial haemorrhage.
- High-risk lesions (GI ulcers, oesophageal varices, aneurysm, malignant tumours with bleeding risk).
- Severe hypersensitivity reaction.
💥 Side Effects
- Bleeding (most serious) → GI, intracranial, or soft tissue.
- GI upset: abdominal pain, nausea, constipation, vomiting.
- Neurological: headache, dizziness (sometimes related to anaemia from bleeding).
- Falls → may worsen risk of traumatic intracranial bleed.
💡 Clinical Pearls
- No routine INR monitoring, but renal function and haemoglobin must be checked regularly.
- Always assess CHA₂DS₂-VASc vs HAS-BLED scores before prescribing.
- Safer than warfarin in most patients, but no easy reversal (andexanet alfa exists but limited availability in UK).
- Counsel patients: 💬 "Take with food, never miss a dose, and report any unexplained bleeding/bruising."
