From the Guidelines
For atrial fibrillation anticoagulation, the recommended dose of anticoagulant is apixaban 5 mg twice daily, or 2.5 mg twice daily for patients with at least two of the following: age ≥80 years, weight ≤60 kg, or serum creatinine ≥1.5 mg/dL, as it has been shown to have a favorable balance of efficacy and safety in preventing stroke and systemic embolism 1.
Anticoagulation Options
The choice of anticoagulant and dose should be based on the patient's individual risk factors, including renal function, age, and weight.
- Apixaban (Eliquis) is commonly used at 5 mg twice daily, or 2.5 mg twice daily for patients with at least two of the following: age ≥80 years, weight ≤60 kg, or serum creatinine ≥1.5 mg/dL.
- Rivaroxaban (Xarelto) is dosed at 20 mg once daily with food, or 15 mg daily with renal impairment (CrCl 15-50 mL/min).
- Dabigatran (Pradaxa) is given as 150 mg twice daily, or 75-110 mg twice daily with renal impairment.
- Edoxaban (Savaysa) is dosed at 60 mg once daily, or 30 mg daily with renal impairment or low body weight.
Stroke Risk Assessment
Anticoagulation decisions should be based on stroke risk (using CHA₂DS₂-VASc score) and bleeding risk. Generally, anticoagulation is recommended for men with a score ≥1 and women with a score ≥2 1.
Rationale
The CHADS2 score is a widely used risk stratification scheme for atrial fibrillation, which assigns points for congestive heart failure, hypertension, age 75 years, diabetes mellitus, and prior stroke or TIA. The score helps guide anticoagulation decisions, with higher scores indicating a greater risk of stroke and a greater benefit from anticoagulation.
Key Considerations
When selecting an anticoagulant, it is essential to consider the patient's individual risk factors, including renal function, age, and weight, as well as their ability to adhere to the prescribed regimen. Regular monitoring of renal function and bleeding risk is also crucial to minimize the risk of adverse events.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Reduction of risk of stroke and systemic embolism in nonvalvular atrial fibrillation: The recommended dose is 5 mg orally twice daily. (2.1) In patients with at least 2 of the following characteristics: age greater than or equal to 80 years, body weight less than or equal to 60 kg, or serum creatinine greater than or equal to 1.5 mg/dL, the recommended dose is 2. 5 mg orally twice daily. (2.1)
The dose of anticoagulant (apixaban) for atrial fibrillation (AFib) is:
- 5 mg orally twice daily for most patients
- 2.5 mg orally twice daily for patients with at least 2 of the following characteristics:
- Age greater than or equal to 80 years
- Body weight less than or equal to 60 kg
- Serum creatinine greater than or equal to 1.5 mg/dL 2
From the Research
Anticoagulant Dose for Atrial Fibrillation
The dose of anticoagulant for atrial fibrillation (AFib) is not explicitly stated in the provided studies. However, the studies discuss the use of various anticoagulants, including warfarin, rivaroxaban, apixaban, and dabigatran, for the prevention of thromboembolic events in patients with AFib.
Anticoagulant Options
- Warfarin is the traditional therapeutic option, with a target international normalized ratio (INR) of 2.00-3.00 3, 4, 5.
- Rivaroxaban is a factor Xa inhibitor that has been approved for the treatment of patients with AFib and a moderate or major risk of thrombosis, with a dose of 20 or 15 mg taken once daily, according to renal function 3, 5.
- Apixaban is another factor Xa inhibitor that has been authorized for use in patients with non-valvular AFib and a moderate or high risk of thrombosis 4.
- Dabigatran is a thrombin inhibitor that is an alternative to warfarin when the INR cannot be maintained within the desired therapeutic range 4, 5.
Considerations for Anticoagulant Use
- The choice of anticoagulant should be based on the individual patient's risk of stroke and hemorrhage, as well as their ability to achieve tight control of vitamin K antagonist (VKA) anticoagulation 6.
- Non-VKA oral anticoagulants (NOACs) have predictable pharmacodynamic and pharmacokinetic properties and are as efficacious as warfarin in preventing stroke and thromboembolism, but are more convenient to use 7, 6.
- The use of anticoagulants should be carefully considered in patients with renal failure, as the anticoagulant action of some drugs may be increased in this population 4, 5.