Apixaban

Brand Names: Eliquis

Drug Class: Direct Factor Xa Inhibitor (Oral Anticoagulant)

Overview

Apixaban is a direct oral anticoagulant (DOAC) that selectively inhibits factor Xa, a key component in the coagulation cascade. It is used for the prevention and treatment of thromboembolic disorders, including stroke prevention in nonvalvular atrial fibrillation, treatment and prevention of deep vein thrombosis (DVT) and pulmonary embolism (PE), and prophylaxis following hip or knee replacement surgery. It offers predictable pharmacokinetics with fixed dosing and does not require routine coagulation monitoring.

Mechanism of Action

Apixaban is a direct, reversible, and highly selective inhibitor of factor Xa (both free and prothrombinase-bound). By inhibiting factor Xa, it decreases thrombin generation and thrombus formation, thereby preventing blood clots.

Indications

  • Reduction of risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation
  • Prophylaxis of deep vein thrombosis (DVT) following hip or knee replacement surgery
  • Treatment of DVT and PE
  • Reduction in the risk of recurrent DVT and PE following initial therapy

Dosage

For nonvalvular atrial fibrillation: 5 mg orally twice daily (2.5 mg twice daily in patients with at least two of the following: age ≥80 years, body weight ≤60 kg, or serum creatinine ≥1.5 mg/dL). For DVT/PE treatment: 10 mg twice daily for 7 days, then 5 mg twice daily. For DVT/PE prophylaxis after hip/knee replacement: 2.5 mg twice daily for 35 days (hip) or 12 days (knee). Take with or without food.

Contraindications

  • Active pathological bleeding
  • Severe hypersensitivity to apixaban or any component of the formulation

Side Effects

  • Bleeding (e.g., hematoma, epistaxis, gastrointestinal bleeding)
  • Nausea
  • Anemia
  • Rash
  • Elevated liver enzymes
  • Hypotension

Interactions

  • Strong dual inhibitors of CYP3A4 and P-gp (e.g., ketoconazole, itraconazole, ritonavir): Increase apixaban exposure; avoid concomitant use.
  • Strong dual inducers of CYP3A4 and P-gp (e.g., rifampin, carbamazepine, phenytoin): Decrease apixaban exposure; avoid concomitant use.
  • Anticoagulants, antiplatelets, NSAIDs: Increase bleeding risk.
  • Herbal supplements like St. John's wort: Decrease apixaban efficacy.