Background:The number of elderly individuals with atrial fibrillation(AF) requiring long-term anticoagulation is rising.The pharmacokinetics of oral anticoagulants in elderly individuals may differ from that for younger patients.
Aim:The aim was to assess the trough and peak anti-Xa activity in elderly xabans-treated and anti-IIa dabigatran-treated patients with AF.
Design:This prospective study enrolled 18 elderly rivaroxaban-treated patients, 16 nonelderly rivaroxaban-treated, 14 elderly apixaban-treated patients, and 10 non-elderly apixaban-treated patients, 21 elderly dabigatran-treated patients and 13 non-elderly patients with AF.
Method:Trough and peak anti-Xa activity was assessed with factor Xa-calibrated anti-Xa chromogenic analysis and anti-IIa activity with the Hemoclot Thrombin Inhibitor Assay.
Results:Comparing elderly and non-elderly rivaroxaban-treated patients, there were no significant differences found in trough (39.9±30.8 vs. 54.1±36.6 ng/mL, p=0.28) and peak (190.9±89.4 vs. 185.7±118.3 ng/mL, p=0.79) anti-Xa activity. Similarly, no significant differences in trough (111.3±69.6 vs. 70.5±41.5 ng/mL, p=0.09) and peak (187.4±81.6 vs. 158.3±91.6 ng/mL, p=0.43) anti-Xa activity were found between apixaban-treated elderly and non-elderly patients with AF. However, there were significant differences in dabigatran trough levels comparing elderly patients with non-elderly patients (99.3 ± 73.6 vs 51.6 ± 25.6 ng/mL; p < 0.01). Similarly, the detected dabigatran peak levels were significantly higher in elderly patients compared with non-elderly patients (173.4 ± 116.2 vs 116.1 ± 19.1 ng/mL; p < 0.01).
Conclusions:This study demonstrated that elderly patients on dabigatran therapy exhibit significantly higher dabigatran levels than non-elderly patients and similar anti-Xa levels in elderly compared to non-elderly xabans treated patients.