Evaluation of Enoxaparin Dosing in Infants Greater Than 2 to 6 Months of Age, a Pre and Post Quasi Experiment.

OBJECTIVE: Enoxaparin is regularly used to treat thromboembolism in children. Numerous retrospective studies suggest that infants and young children require higher enoxaparin doses to achieve therapeutic anti-factor Xa (AXA) concentration of 0.5 to 1.0 units/mL compared with adults. METHODS: This is a retrospective analysis of pre- and post-implementation of an increased initial dose of enoxaparin (1.2 mg/kg every 12 hours) for infants between 2 and 6 months of age. The objective is to compare the number of dose adjustments needed to achieve therapeutic AXA. RESULTS: A total of 64 patients were included 30 pre- and 34 post-guideline groups. In both the pre- and post-guideline dosing groups the number of dose adjustments required to achieve therapeutic AXA when adjusted per the ACCP guidelines was a median of 1 (p = 0.35). However, the first initial AXA was 0.3 units/mL in the pre-guideline group and 0.48 units/mL in the post-guideline group (p = 0.07). There were no documented instances of major bleeding events in either group. CONCLUSION: The results support the recommendation of an increased enoxaparin starting dose for therapeutic anticoagulation in the described patient population at the study site. A large prospective study is needed to determine specific dose recommendations that will achieve therapeutic AXA concentrations for the majority of infants and children of all ages.