Major
Apixaban × Dronedarone
Direct oral anticoagulants (factor Xa inhibitors)×Class III antiarrhythmic
Mechanism
Dronedarone is a strong P-glycoprotein and CYP3A4 inhibitor – two apixaban clearance routes. Apixaban plasma levels rise by 30–60%; bleeding risk increases.
Symptoms
Gum bleeding, epistaxis, bruising without trauma, black stools, blood in urine. Severe cases include gastrointestinal or intracranial haemorrhage.
Management
The combination is acceptable without dose change in patients under 80, weight above 60 kg, serum creatinine below 133 µmol/L. In older patients with two of these factors, reduce apixaban to 2.5 mg twice daily.