Evaluation of Enoxaparin Dosing and Monitoring in Pediatric Patients at Children's Teaching Hospital.

Abstract

The primary objective of this study was to evaluate whether empirical enoxaparin doses according to Chest guidelines resulted in therapeutic antifactor Xa concentrations in pediatric patients. Secondary objectives were to determine the median enoxaparin dose that resulted in therapeutic anticoagulation, the median time to therapeutic concentrations, and the percentage of patients who experienced major bleeding. Patients in a tertiary medical center who were <18 years of age and received treatment doses of enoxaparin between July 2007 and June 2010 were included. Patients with <2 antifactor Xa concentrations or with only supratherapeutic concentrations and doses that were higher than recommended by the guidelines were excluded. Subgroup analysis was conducted by dividing children into 4 age groups: <2 months of age, 2 months to <1 year of age, 1 year to <3 years of age, and 3 to 17 years of age. Thirty-two patients were included in the study. Thirty-seven percent of the patients achieved a therapeutic drug level with empirical dosing. The therapeutic dose ranged from 1 to 1.9 mg/kg in patients <1 year old, and 0.6 to 1.5 mg/kg in those =1 year of age. Comparison of the median therapeutic doses for patients 2 months to <1 year to that for patients =1 year old using the Mann-Whitney U test showed the median doses to be significantly difierent between the 2 groups (p=0.01). The antifactor Xa level became therapeutic on day 5 (median). There were no major bleeding events. Less than 40% of patients were therapeutic with empirical dosing, which supports findings from other studies that suggest a need for modification of empirical treatment dosing of enoxaparin in children.