Safety and efficacy of thromboprophylaxis with fondaparinux in elderly acutely ill medical patients with renal impairment: a retrospective single center study

The majority of acutely ill medical patients are elderly with some degree of renal impairment. In this setting, venous thromboembolism (VTE) is one of the leading causes of morbidity and mortality and, to reduce this risk, a correct thromboprophylaxis is needed. The aim of this single center retrospective study was to assess the safety and efficacy of fondaparinux in elderly acutely ill medical patients with renal impairment. All patients aged 60 years or over, bedridden for at least four days, with a creatinine clearance (CrCl) of 50 mL/min or under, and who had received fondaparinux during hospitalization were evaluated and followed for up to 90 days after discharge. A total of 125 patients were evaluated (34.4% males); median age was 83.0 years. Median duration of thromboprophylaxis was 9.0 days. Forty-one (32.8%) patients were treated with fondaparinux 1.5 mg daily, 84 (67.2%) with 2.5 mg daily. Inappropriately high doses of fondaparinux were used in 77 patients with CrCl 20-50 mL/min, in 12 patients with CrCl below 20 mL/min, in 14 patients with prothrombin time (PT) ratio over 1.2, in 8 patients with PT ratio over 1.5, and in 3 patients with thrombocytopenia. No episodes of VTE or of major bleeding were recorded while there were 6 episodes (2.4%) of minor bleeding. Both dosages of fondaparinux showed similar safety and efficacy. Twenty-six patients (20.8%) died; no cause of death was related to fondaparinux. In conclusion, in elderly acutely ill hospitalized medical patients with renal impairment, prophylaxis with fondaparinux 2.5 or 1.5 mg daily is safe and effective in preventing VTE without increasing bleeding risk.