Edoxaban

1. Introduction

Edoxaban is a direct oral anticoagulant (DOAC) that works by selectively inhibiting Factor Xa, a critical component in the blood clotting cascade. It is used to prevent and treat thromboembolic disorders, such as stroke, systemic embolism, and venous thromboembolism (VTE). Edoxaban offers an alternative to traditional anticoagulants like warfarin due to its predictable pharmacokinetics and lack of routine monitoring requirements.

2. Indications

  • Approved Indications:
    • Prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF).
    • Treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE) following initial therapy with a parenteral anticoagulant for 5–10 days.
  • Off-Label Uses:
    • Thromboprophylaxis in cancer-associated thrombosis (in selected cases).

3. Dosage

  • Adults:
    • Stroke Prevention in NVAF: 60 mg once daily.
      • Reduce to 30 mg once daily in patients with:
        • Creatinine clearance (CrCl) 15–50 mL/min.
        • Body weight ≤60 kg.
        • Concomitant use of certain P-glycoprotein inhibitors (e.g., cyclosporine, dronedarone).
    • DVT/PE Treatment:
      • Initial therapy with a parenteral anticoagulant for 5–10 days, then 60 mg once daily.
      • Reduce dose to 30 mg once daily in the same conditions as NVAF.
  • Elderly:
    • No specific dose adjustment is required solely based on age, but renal function must be considered.

4. Administration

  • Take orally with or without food.
  • Ensure consistent timing of doses to maintain steady anticoagulant levels.

5. Forms Available

  • Tablets: 15 mg, 30 mg, 60 mg.

6. Side Effects

6.1. Common Side Effects

  • Bleeding (e.g., bruising, nosebleeds, gastrointestinal bleeding).
  • Anaemia.
  • Nausea.

6.2. Less Common Side Effects

  • Rash or itching.
  • Elevated liver enzymes.

6.3. Rare but Serious Side Effects

  • Severe bleeding (e.g., intracranial haemorrhage, life-threatening bleeding).
  • Allergic reactions (e.g., angioedema, anaphylaxis).

7. Warnings

  • Bleeding Risk: Use cautiously in patients at increased risk of bleeding, including those with a history of gastrointestinal bleeding or recent surgery.
  • Renal Function: Reduced efficacy in patients with CrCl >95 mL/min, as it may lead to lower plasma levels.
  • Hepatic Impairment: Avoid use in patients with moderate to severe hepatic impairment due to potential bleeding risks.

8. Precautions

  • Discontinue at least 24 hours before elective surgery or invasive procedures to reduce bleeding risk.
  • Avoid in patients with mechanical heart valves or moderate to severe mitral stenosis, as it has not been studied in these populations.
  • Use cautiously in patients with low body weight (<50 kg) due to higher drug exposure.

9. Interactions

  • Drug-Drug Interactions:
    • Strong P-glycoprotein inhibitors (e.g., cyclosporine, dronedarone, erythromycin, ketoconazole): May increase edoxaban levels.
    • Strong P-glycoprotein inducers (e.g., rifampin, phenytoin): May decrease edoxaban levels.
    • Antiplatelets and NSAIDs: Increased risk of bleeding.
  • Drug-Food Interactions:
    • No significant food interactions, but taking with food may improve gastrointestinal tolerance.

10. Monitoring Parameters

  • Renal function (e.g., CrCl) prior to initiation and periodically during treatment.
  • Signs and symptoms of bleeding (e.g., prolonged bleeding, bruising).
  • Liver function tests in patients with pre-existing liver conditions.

11. Use in Children

  • Safety and efficacy have not been established in children. Not recommended.

12. Use in Pregnancy

  • Category C: Use only if potential benefits justify the potential risks to the foetus. Limited human data is available.

13. Use in Elderly

  • Safe for use in elderly patients, but renal function and bleeding risk should be carefully monitored.

14. Use in Kidney Disease

  • Dose adjustment is required in patients with CrCl 15–50 mL/min (30 mg once daily).
  • Avoid use in patients with CrCl <15 mL/min.

15. Use in Liver Disease

  • Avoid use in patients with moderate to severe hepatic impairment due to increased bleeding risk and lack of data.

16. Patient Counselling Points

  • Take edoxaban exactly as prescribed, without skipping doses.
  • Inform your doctor of any signs of bleeding, such as dark stools, prolonged bleeding from cuts, or unusual bruising.
  • Avoid taking other anticoagulants or NSAIDs unless advised by your doctor.
  • Let all healthcare providers, including dentists, know that you are taking edoxaban before undergoing procedures.
  • Do not stop taking edoxaban without consulting your doctor, as it may increase your risk of blood clots.

17. Table of Brand Names, Manufacturers, and Prices

Brand NameManufacturerPrice (USD)
SavaysaDaiichi Sankyo$350–450 (30 tablets, 60 mg)
LixianaDaiichi Sankyo$300–400 (30 tablets, 60 mg)
Generic EdoxabanVarious$200–300 (30 tablets, 60 mg)

18. FAQs (15 Questions)

  1. What is edoxaban used for?
    It is used to prevent stroke and systemic embolism in non-valvular atrial fibrillation and to treat DVT and PE.
  2. How does edoxaban work?
    It inhibits Factor Xa, reducing the formation of blood clots.
  3. How should edoxaban be taken?
    Take it once daily, with or without food, at the same time each day.
  4. Can edoxaban cause bleeding?
    Yes, bleeding is the most common side effect. Report any unusual bleeding or bruising to your doctor immediately.
  5. Is edoxaban safe during pregnancy?
    It should only be used if absolutely necessary, as there is limited safety data in pregnancy.
  6. Can edoxaban interact with other medications?
    Yes, it interacts with antiplatelets, NSAIDs, and drugs that affect P-glycoprotein activity.
  7. Do I need regular blood tests while taking edoxaban?
    No routine blood monitoring is required, but renal and liver function should be checked periodically.
  8. Can edoxaban be stopped suddenly?
    No, stopping edoxaban suddenly may increase the risk of blood clots. Consult your doctor before discontinuing.
  9. Is edoxaban effective for patients with good kidney function?
    It may be less effective in patients with CrCl >95 mL/min, as plasma levels may be lower.
  10. What should I do if I miss a dose of edoxaban?
    Take it as soon as you remember, but skip it if it’s close to the next dose. Do not double the dose.
  11. Can edoxaban be used in children?
    No, it is not approved for use in children.
  12. Can I drink alcohol while taking edoxaban?
    It is best to limit alcohol consumption, as it may increase the risk of bleeding.
  13. How long does edoxaban stay in the system?
    The half-life is approximately 10–14 hours, but its effects can last up to 24 hours.
  14. Can edoxaban cause weight gain?
    No, weight gain is not a known side effect.
  15. How should edoxaban be stored?
    Store at room temperature, away from moisture and heat.