Low-molecular-weight heparin in pediatric patients with thrombotic disease: A dose finding study

Objective: To compare low-molecular-weight preparations of heparin (LMWH) with standard heparin in children requiring anticoagulant treatment for thromboembolic disease. Methods: We treated 25 children who required heparin, but were at significant risk of bleeding, with LMWH (enoxaparin, Rhone-Poulenc Rorer), The median age was 4 years (range, newborn to 17 years); with nine infants less than 2 months of age, Fourteen children had a deep vein thrombosis or pulmonary embolism, nine had thrombotic complications in the central nervous system, and two had complex congenital heart disease, for which they received prophylaxis at a lower dosage (0.5 mg/kg given subcutaneously twice a day), The remaining 23 children received an initial dose of 1 mg/kg, every 12 hours subcutaneously, with subsequent doses adjusted to achieve a 4-hour anti-factor Xa level between 0.5 and 1.0 unit/ml. Results: Newborn infants had increased dose requirements; an average of 1.60 units/kg was required to achieve therapeutic heparin levels, For the remaining children, the initial dose of 1.0 mg/kg was sufficient. After the initial dose adjustment, LMWH was administered with twice-weekly monitoring, The median duration of therapy with LMWH was 14 days. Two children with previously documented gastrointestinal ulcers bled and required transfusion therapy. Therapy with LMWH was continued without further events. There were no new thrombotic events during the treatment with LMWH. The cost of administering LMWH compared with heparin was reduced by 30% because of decreased laboratory monitoring, blood sampling times, intravenous starts, and nursing time. Needle punctures were reduced with LMWH therapy by the placement of a subcutaneous catheter. Conclusion: These results provide the basis for a randomized, controlled trial comparing LMWH with standard heparin in pediatric patients.