Drug reactions a risk with NOAC treatment for afib
Patients with nonvalvular atrial fibrillation may have a higher risk for adverse events and death if they are taking non-vitamin K oral anticoagulants (NOACs) with medications such as digoxin, diltiazem, and amiodarone, a recent study in Hong Kong found.
Certain drugs may cause adverse events when taken with non-vitamin K oral anticoagulants (NOACs) for nonvalvular afib, according to a recent study.
Researchers in Hong Kong performed a retrospective cohort study in patients with nonvalvular atrial fibrillation who were taking NOACs, with the goal of determining whether concomitant medications were associated with risk for gastrointestinal bleeding, intracranial hemorrhage, hospitalization for major bleeding, and all-cause mortality. The results of the study, which was funded by an unrestricted educational grant from Daiichi Sankyo Hong Kong Limited, were published April 17 by the Journal of the American Heart Association.
A total of 22,568 patients with nonvalvular atrial fibrillation who were taking NOACs in 2017 to 2020 were included in the analysis. Of these, 11,601 were taking apixaban, 6,963 were taking dabigatran, 3,230 were taking rivaroxaban, and 774 were taking edoxaban. Mean age was 75.7 years, and 51.2% were men. Atorvastatin (26.4%), digoxin (19.0%), diltiazem (14.4%), and amiodarone (13.9%) were the most commonly prescribed concomitant drugs that could potentially interact with a NOAC.
The researchers found increased gastrointestinal bleeding in patients on amiodarone (hazard ratio [HR], 1.53), digoxin (HR, 1.30), diltiazem (HR, 1.18), clarithromycin (HR, 4.98), and fluconazole (HR, 2.38); amiodarone and digoxin were also associated with increased intracranial hemorrhage (HRs, 2.20 and 1.61, respectively). Higher risk for hospitalization due to major bleeding was associated with amiodarone (HR, 1.64), digoxin (HR, 1.35), clarithromycin (HR, 4.18), and fluconazole (HR, 2.40), while higher all-cause mortality was seen with amiodarone (HR, 2.65), digoxin (HR, 1.85), diltiazem (HR, 1.44), verapamil (HR, 1.80), antidepressants (HR, 1.31), and fluconazole (HR, 3.27). A significant reduction in all-cause mortality was associated with dronedarone (HR, 0.56) and atorvastatin (HR, 0.86).
Among other limitations, information about patients' body weight, which can affect NOAC dosing, and periods of exposure to concomitant medications was lacking, the authors wrote. They concluded that among patients with nonvalvular atrial fibrillation taking NOACs, several concurrent medications were associated with higher risk of intracranial hemorrhage, major bleeding hospitalizations, and overall mortality. “Understandably, it may be occasionally necessary to prescribe medications that are known to interact with an NOAC when there is no alternative therapeutic option,” the authors wrote. However, they called for clinicians “to be vigilant of the increased risk of bleeding and even all-cause mortality when these combination therapies are prescribed.”