Enoxaparin - effective dosage for intensive care patients: double-blinded, randomised clinical trial.
Crit Care. 2010 Mar 18;14(2):R41
Authors: Robinson S, Zincuk A, Strom T, Larsen TB, Rasmussen B, Toft P
ABSTRACT: INTRODUCTION: Intensive care unit (ICU) patients are predisposed to thromboembolism. Routine prophylactic anticoagulation is widely recommended. Low-molecular-weight heparins such as enoxaparin, are increasingly utilised due to predictable pharmacokinetics. This study aims to determine the subcutaneous (sc) dose of enoxaparin, which would give the best anti-factor Xa levels in ICU patients. METHODS: 72 patients admitted to a mixed ICU at Odense University Hospital (OUH) in Denmark were randomised into 4 groups to receive 40, 50, 60 or 70 mg sc enoxaparin for a period of 24 hours. Anti-factor Xa activity (aFXa) was measured before, and at 4, 12, and 24 hours post administration. AFXa between 0.1 to 0.3 IU/ml was considered evidence of effective antithrombotic activity. RESULTS: Median peak (= 4 hours post administration) aFXa levels increased significantly with an increase in enoxaparin dose, from: 0.13 IU/ml at 40 mg, to 0.14 IU/ml at 50 mg, 0.27 IU/ml at 60 mg and 0.29 IU/ml at 70 mg respectively (P = 0.002*) . At 12 hours post administration, median aFXa levels were still within therapeutic range for those patients who received 60 mg (P= 0.02). CONCLUSIONS: Our study confirmed that a standard dose of 40 mg enoxaparin yielded sub- therapeutic levels of aFXa in critically ill patients. Higher doses resulted in better peak aFXa levels, with a ceiling effect observed at 60 mg. The present study seems to suggest inadequate dosage as one of the possible mechanisms for the higher failure rate of enoxaparin in ICU patients. Trial Registration: ISRCTN03037804.
PMID: 20298591 [PubMed - as supplied by publisher]