LOW-MOLECULAR-WEIGHT HEPARIN IN PEDIATRIC-PATIENTS WITH THROMBOTIC DISEASE - A DOSE-FINDING STUDY

Objective: To compare low-molecular-weight preparations of heparin (LM WH) with standard heparin in children requiring anticoagulant treatmen t for thromboembolic disease. Methods: We treated 25 children who requ ired heparin, but were at significant risk of bleeding, with LMWH (eno xaparin, Rhone-Poulenc Rorer), The median age was 4 years (range, newb orn to 17 years); with nine infants less than 2 months of age, Fourtee n children had a deep vein thrombosis or pulmonary embolism, nine had thrombotic complications in the central nervous system, and two had co mplex congenital heart disease, for which they received prophylaxis at a lower dosage (0.5 mg/kg given subcutaneously twice a day), The rema ining 23 children received an initial dose of 1 mg/kg, every 12 hours subcutaneously, with subsequent doses adjusted to achieve a 4-hour ant i-factor Xa level between 0.5 and 1.0 unit/ml. Results: Newborn infant s had increased dose requirements; an average of 1.60 units/kg was req uired to achieve therapeutic heparin levels, For the remaining childre n, the initial dose of 1.0 mg/kg was sufficient. After the initial dos e adjustment, LMWH was administered with twice-weekly monitoring, The median duration of therapy with LMWH was 14 days. Two children with pr eviously documented gastrointestinal ulcers bled and required transfus ion therapy. Therapy with LMWH was continued without further events. T here were no new thrombotic events during the treatment with LMWH. The cost of administering LMWH compared with heparin was reduced by 30% b ecause of decreased laboratory monitoring, blood sampling times, intra venous starts, and nursing time. Needle punctures were reduced with LM WH therapy by the placement of a subcutaneous catheter. Conclusion: Th ese results provide the basis for a randomized, controlled trial compa ring LMWH with standard heparin in pediatric patients.