Rivaroxaban

1. Introduction

Rivaroxaban is an oral anticoagulant and a direct factor Xa inhibitor. It is used to prevent and treat blood clots, such as deep vein thrombosis (DVT) and pulmonary embolism (PE). It is also used to reduce the risk of stroke in patients with non-valvular atrial fibrillation. By inhibiting factor Xa, rivaroxaban prevents the formation of fibrin clots without requiring routine monitoring.

2. Indications

  • Prevention of stroke and systemic embolism: In patients with non-valvular atrial fibrillation.
  • Treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE): To reduce the risk of recurrence.
  • Prevention of DVT/PE: After hip or knee replacement surgery.
  • Reduction of cardiovascular events: In patients with coronary artery disease (CAD) or peripheral artery disease (PAD).

3. Dosage

Adults:

  • Non-valvular atrial fibrillation (stroke prevention): 20 mg once daily with food.
    • For patients with moderate renal impairment (CrCl 15–50 mL/min): 15 mg once daily with food.
  • DVT/PE treatment: 15 mg twice daily with food for the first 21 days, followed by 20 mg once daily with food.
  • Prevention of DVT/PE (hip or knee replacement): 10 mg once daily, starting 6–10 hours after surgery.
    • Duration: 14 days for knee replacement, 35 days for hip replacement.
  • CAD/PAD (cardiovascular risk reduction): 2.5 mg twice daily with aspirin (75–100 mg daily).

Elderly:

  • No dose adjustment is necessary, but renal function should be monitored.

Children:

  • Not recommended for use in paediatric patients.

4. Administration

  • Take tablets with food to improve absorption, especially doses of 15 mg or more.
  • For patients unable to swallow tablets, rivaroxaban may be crushed and mixed with water or apple puree, followed by immediate consumption.

5. Forms Available

  • Tablets: 2.5 mg, 10 mg, 15 mg, 20 mg

6. Side Effects

6.1 Common Side Effects:

  • Bleeding (e.g., nosebleeds, gum bleeding)
  • Bruising
  • Nausea

6.2 Less Common Side Effects:

  • Anaemia
  • Fatigue
  • Dizziness

6.3 Rare but Serious Side Effects:

  • Major bleeding (e.g., gastrointestinal, intracranial)
  • Severe allergic reactions (e.g., angioedema, rash)
  • Hepatotoxicity (liver enzyme elevations)

7. Warnings

  • Bleeding Risk: Use cautiously in patients with an increased risk of bleeding (e.g., recent surgery, gastrointestinal ulcers, or concomitant use of other anticoagulants).
  • Spinal/Epidural Haematoma: Increased risk of haematomas during spinal puncture or epidural anaesthesia, potentially leading to paralysis.
  • Renal Impairment: Adjust dose in patients with reduced renal function (CrCl <50 mL/min). Avoid use if CrCl <15 mL/min.
  • Discontinuation Risk: Stopping rivaroxaban prematurely increases the risk of thrombotic events.

8. Precautions

  • Avoid use in patients with active bleeding or severe liver disease associated with coagulopathy.
  • Use cautiously in elderly patients, who are at higher risk of bleeding.
  • Avoid in pregnancy and lactation unless the benefit outweighs the risk.

9. Interactions

  • CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): Increased rivaroxaban levels and bleeding risk.
  • CYP3A4 inducers (e.g., rifampin, carbamazepine): Reduced efficacy of rivaroxaban.
  • Anticoagulants/Antiplatelets (e.g., aspirin, clopidogrel): Increased bleeding risk.
  • NSAIDs: Higher risk of gastrointestinal bleeding.

10. Monitoring Parameters

  • Assess renal function (e.g., serum creatinine, CrCl) before initiating therapy and periodically during treatment.
  • Monitor for signs of bleeding (e.g., haematuria, black stools).
  • Evaluate liver function if clinical signs of hepatotoxicity occur.

11. Use in Children

  • Not approved for use in children or adolescents under 18 years of age.

12. Use in Pregnancy

  • Category C: Use only if the potential benefit outweighs the risk. Avoid use in late pregnancy due to the risk of foetal bleeding.

13. Use in Elderly

  • Safe for use in elderly patients at standard doses. Monitor closely for renal function and bleeding risks.

14. Use in Kidney Disease

  • CrCl 15–50 mL/min: Dose adjustments required.
  • CrCl <15 mL/min: Contraindicated.

15. Use in Liver Disease

  • Contraindicated in patients with significant liver disease associated with coagulopathy.

16. Patient Counselling Points

  • Take rivaroxaban exactly as prescribed, with food if required, and do not skip doses.
  • Inform your doctor if you notice unusual bleeding, bruising, or signs of severe bleeding (e.g., black stools, coughing up blood).
  • Avoid combining rivaroxaban with NSAIDs or other blood-thinning medications without medical advice.
  • Discuss any upcoming surgeries or dental procedures with your doctor, as rivaroxaban may need to be stopped beforehand.
  • Avoid alcohol, as it may increase the risk of bleeding.

17. Table of Brand Names, Manufacturer, and Prices in USD

Brand NameManufacturerStrength/Dosage FormPrice (USD)
XareltoBayer20 mg Tablet$450 (30 tablets)
Generic RivaroxabanVarious20 mg Tablet$300 (30 tablets)

18. 15 FAQs (Frequently Asked Questions)

1. What is Rivaroxaban used for?
It is used to prevent and treat blood clots (DVT, PE) and reduce the risk of stroke in atrial fibrillation.

2. How does Rivaroxaban work?
It inhibits factor Xa, preventing the formation of blood clots.

3. Can Rivaroxaban cause bleeding?
Yes, bleeding is the most common side effect.

4. Should Rivaroxaban be taken with food?
Yes, doses of 15 mg or more should be taken with food for optimal absorption.

5. Can Rivaroxaban be used during pregnancy?
It is generally not recommended unless the benefits outweigh the risks.

6. What should I do if I miss a dose of Rivaroxaban?
Take the missed dose as soon as you remember on the same day. Do not double doses.

7. Can Rivaroxaban be stopped suddenly?
No, stopping abruptly increases the risk of blood clots. Consult your doctor before discontinuing.

8. Can Rivaroxaban be taken with aspirin?
Yes, but only under medical supervision, as the combination increases bleeding risk.

9. Does Rivaroxaban require blood monitoring?
Routine monitoring is not required, but periodic kidney and liver function tests may be needed.

10. Can Rivaroxaban be crushed?
Yes, tablets can be crushed and mixed with water or puree for patients unable to swallow.

11. How long is Rivaroxaban prescribed after surgery?
14 days for knee replacement and 35 days for hip replacement.

12. Can Rivaroxaban cause liver problems?
Rarely, it may cause elevated liver enzymes or hepatotoxicity.

13. Is Rivaroxaban safe for elderly patients?
Yes, but they should be monitored for bleeding risks.

14. Can Rivaroxaban interact with antibiotics?
Yes, certain antibiotics (e.g., erythromycin) may increase bleeding risk.

15. What should I do if I experience severe bleeding on Rivaroxaban?
Seek immediate medical attention.