Low-Dose Apixaban May Prevent Strokes in Dialysis Patients with Atrial Fibrillation

Small doses of the anticoagulant apixaban (Eliquis) were observed to prevent strokes in patients with atrial fibrillation who were undergoing dialysis for kidney failure, according to a study published by the Journal of the American Society of Nephrology.

Patients with kidney failure treated with dialysis also tend to have atrial fibrillation, which places them at a high risk of experiencing a stroke. The anticoagulant warfarin is commonly prescribed and reduces the risk of stroke in patients with atrial fibrillation, but its use among patients undergoing dialysis is currently unknown.

The study authors chose to examine the efficacy of apixaban in preventing strokes, since it more directly inhibits coagulation than warfarin.

Apixaban is an oral selective Factor Xa inhibitor, which is a blood clotting protein, and has been observed to reduce thombin generation and blood clots. The drug has been approved to lower the risk of stroke and systemic embolism in patients with non-valvular atrial fibrillation; prophylaxis of deep vein thrombosis; treatment of deep vein thrombosis and pulmonary embolism; and prevent recurrence of the conditions.

Included in the new study were 7 patients treated with dialysis for kidney failure who received low-dose apixaban (2.5-mg) twice per day to prevent strokes.

When the investigators gathered blood samples, they discovered accumulation of the drug between days 1 and 8. When monitored hourly during dialysis, only 4% of the drug was removed, according to the study.

After a 5-day washout period, 5 patients received 5-mg of apixaban twice per day for 8 days. The authors noted that when these patients took the recommended 5-mg dose, they experienced significantly higher levels of the drug in the blood.

Due to the dangerously high levels of apixaban, the researchers said that the lower dose would be a safer treatment option. However, more studies are needed before apixaban can be recommended as the standard of care for patients with atrial fibrillation undergoing dialysis.

"This dosage should be avoided in patients on dialysis. On the contrary, drug exposure with the reduced dose of 2.5-mg twice daily may be considered in patients on dialysis with atrial fibrillation," Dr Mavrakanas said. "No clinical data are yet available, however, and more evidence is necessary before recommending this drug at the 2.5-mg twice daily dose for stroke prevention in patients on dialysis with atrial fibrillation."