A first-of-its-kind exploratory study finds that over half of frail, older patients admitted to the hospital for acute illness and are on blood thinners from the direct oral anticoagulant (DOAC) class had DOAC drug levels outside of the recommended range. This is a particular challenge for frail, older patients due the population’s increased susceptibility to thromboembolism and bleeding.
Authors of The DOAC-FRAIL study, evaluation of direct oral anticoagulant-levels in acutely admitted frail older patients, suggest that out-of-range levels link directly to a general lack of DOAC management guidelines.
To fill this knowledge gap and shed light on essential anticoagulant management, researchers examined the DOAC levels in 42 frail patients aged 65+ who were hospitalized for acute illnesses, such as an infection. The study concluded that 54.8% of patients had non-ideal DOAC levels, with 40.5% above and 14.3% below the recommended therapeutic range.
Patients admitted for infections were less likely to have excessive levels, possibly due to changes in how the drugs are absorbed and metabolized during illness. Those with poorer kidney function and taking the DOAC rivaroxaban trended more often to high levels, though impaired renal function alone could not fully explain the variations. In addition, patients taking proton pump inhibitor medications were less prone to low DOAC levels, though the reasons remain unclear.
The authors summarized that DOAC management is increasingly important due to recent findings that show higher rates of bleeding in frail older patients with atrial fibrillation (AF) who switched from vitamin K antagonists (VKA) to a DOAC. A possible reason for this, the authors added, may be variations in how different patients respond to different DOAC doses.
While DOACs were designed to eliminate routine lab monitoring, as needed for older blood thinners, this exploratory study highlights how acute medical issues and patient factors may significantly impact drug levels in frail older adults. The researchers emphasized that there is a complex interplay of factors influencing DOAC levels and individualized dosing approaches in this population during hospital stays may be necessary.
