Retrospective comparison of two enoxaparin dosing and monitoring protocols at a pediatric hospital

Abstract

The study analyzes the effectiveness and safety of a higher than standard enoxaparin dosing protocol implemented for pediatric patients requiring initiation of therapeutic anticoagulation. A retrospective review of 2 enoxaparin dosing and monitoring protocols was performed. The standard protocol used 1.5 mg/kg/dose (in patients <3 months of age) and 1 mg/kg/dose (in patients ≥3 months of age) with anti-Xa monitoring following the first dose. The high-dose protocol was implemented at 1.7 mg/kg/dose (in patients <3 months of age), 1.5 mg/kg/dose (in patients 3 through 11 months of age), 1.2 mg/kg/dose (in patients 1 through 4 years of age), and 1.1 mg/kg/dose (in patients 5 through 17 years of age), with anti-Xa monitoring after the second dose. Primary outcomes were number of dosing changes prior to and time to first target anti-Xa level. Secondary outcomes included percentage of patients with anti-Xa levels above target level. The median number of dose changes required to achieve a target anti-Xa level was 1 (interquartile range [IQR], 0-1.5) and 0 (IQR, 0-1) for the standard-dose (n = 87) and high-dose groups (n = 132) (p = 0.17), respectively. The median number of dose adjustments to achieve target anti-Xa levels in the 3 through 11 months of age subgroup declined from 2 (IQR, 1-3.25) to 0 (IQR, 0-1) in the standard- versus high-dose groups, respectively (p < 0.01). No difference was seen in other age subgroups. Patients with above-target levels did not differ statistically between groups. Initiating enoxaparin at higher doses in pediatric patients may result in fewer dosing changes than standard dosing. Benefit was demonstrated for the 3-11 months of age high-dose subgroup. Across all groups, the high-dose strategy was safe and did not result in a statistically significant increase in above-target levels.