Effect of Antiepileptic Drugs on Bone Metabolism and Growth in Epileptic Children

ABSTRACT

PURPOSE: Long-term administration of anticonvulsants for children with convulsive disorder may cause osteomalacia, depending on dosage, duration, types, and combination of anticonvulsants administered. This study was performed to examine the effect of anticonvulsant drugs on bone mineral density in epileptic children. METHODS: Forty-eight epileptic children aged 3 to 15 years were enrolled in this study. They were treated with antiepileptic drugs such as carbamazepine(group I), valproic acid(group II), or a combination of several drugs(group III) for long periods time from 6 months to 84 months. Bone mineral density was measured using dual energy absorptiometry(Madison, Wisconsin, U.S.) on the lumbar vertebrae during the period of Dec. 1, 1996-Jul. 1, 1997. Calcium, phosphorus, and alkaline phosphatase were also concomitantly measured in the sera of subjects for comparative analysis. Statistical analysis was performed using drugs and duration of therapy through specific z-score. Analysis for bone mineral density of anticonvulsant treated subjects were compared to results with published data. RESULTS: Bone mineral density was significantly decreased only in the carbamazepine-treated group, especially in children who received carbamazepine therapy for more than 18months. Z-scores of the other groups were also slightly decreased though they were not significant. And serum concentration of calcium and phosphorus levels were within normal ranges, but alkaline phosphatase levels were significantly increased(P<0.01). CONCLUSION: Measurement of bone mineral density might be required in epileptic children who received antiepileptic drugs. Administration of vitamin D should also be recommended in epileptic children, especially if they have been treated with antiepileptic drugs for a long time.