Apixaban anti-Xa level monitoring in treatment of acute upper extremity deep vein thrombosis for patient on chronic hemodialysis: a case report

BACKGROUND: Patients on dialysis are at higher risk of major bleeding and recurrent thrombosis creating acute venous thromboembolism (VTE) treatment challenges. DOACs represent an interesting option but there are concerns of bioaccumulation and increased bleeding risk. Anti-Xa trough levels may be used to monitor for bioaccumulation but there is little data. CASE PRESENTATION: We describe a case, a 51 yo female, 36 kg on hemodialysis with a provoked acute upper extremity deep vein thrombosis in whom body habitus and calciphylaxis contraindicated the use of standard therapy. She received apixaban 2.5 mg twice daily for 6 weeks. The apixaban anti-Xa trough levels were measured weekly 12 h after the morning dose and ranged from 58 to 84 ng/mL, similar to expected levels with normal renal function. There were no adverse events in the 3 months follow-up. CONCLUSIONS: We saw no evidence of bioaccumulation indicating a potential role for low dose apixaban for acute VTE in dialysis patients.