The DOAC-FRAIL Study-Same Dose, Different Story: Prevalence of Deviant Direct Oral Anticoagulant Levels in Nursing...

Direct oral anticoagulants (DOACs) are prescribed using fixed dosing regimens, despite limited evidence on their pharmacokinetic behavior in nursing home residents.

One hundred nursing home residents are receiving apixaban, rivaroxaban, dabigatran, or edoxaban in multiple long-term care facilities in the Netherlands.

In this prospective observational study, DOAC peak levels were measured 2-4 h post-dose during routine laboratory testing. Levels were classified as below, within, or above the expected on-therapy range. Logistic regression analyses identified factors associated with peak levels outside the expected on-therapy range.

Overall, 40% of residents had DOAC peak levels outside the expected on-therapy range; 32% were above and 8% were below. In univariable analyses, above-range levels were associated with lower renal function, apixaban use, and history of myocardial infarction, but none remained independently associated after multivariable adjustment. Below-range levels were associated with preserved renal function and rivaroxaban use; analyses for below-range levels were limited to univariable analyses due to the small number of events.

A substantial proportion of nursing home residents exhibited DOAC peak levels outside the expected on-therapy range despite guideline-concordant dosing. These findings highlight the complexity of anticoagulant management in frail older adults residing in long-term care and support the need for careful clinical reassessment of DOAC therapy in this population.