An audit of apixaban prescribing for atrial fibrillation in a hospital setting

The oral anticoagulant apixaban is becoming a popular first-line option for prevention of stroke and systemic embolism, in adults with non-valvular atrial fibrillation (NVAF) exhibiting one or more risk factors. Two dosage regimens are recommended: 5mg twice daily or 2.5mg twice daily; the latter is deemed appropriate if creatinine clearance (CrCl) 15-29 ml/min or at least two of age ≥ 80 years, body weight ≤ 60 kg, or serum creatinine ≥ 133 micromol/L are satisfied. These criteria derive from results of two large successful clinical trials1,2 and have formed the basis of local prescribing guidelines. This audit has shown that current evidence-based guidelines are not being fully adhered to, especially when prescribing for elderly patients. Consequently, these patients are potentially put at risk of subtherapeutic dosing, in turn increasing their probability of stroke. Current published evidence does not justify reducing doses based solely on age, despite anecdotal concerns of local prescribers of an increased risk of haemorrhage. Prescribers should remain vigilant and document any reasons for dosing the product outside of its licence.