EFFECT OF CARBAMAZEPINE AND VALPROATE ON BONE-MINERAL DENSITY

Objective: To examine the effect of carbamazepine and valproate monoth erapy on bone mineral density in children. Methods: Axial (second, thi rd, and fourth lumbar vertebrae) and appendicular (distal third of rad ius) bone mineral density was measured by dual-energy x-ray absorptiom etry in 27 healthy children and 26 children with uncomplicated idiopat hic epilepsy treated with either carbamazepine (n = 13) or valproate ( n = 13) for more than 18 months. Control subjects and patients were si milar with respect to age, race (all white), and geographic area, and had no dietary restrictions, neurologic impairment, or physical handic aps. Results: Subjects were seizure-free for more than 6 months on a r egimen of carbamazepine or valproate therapy, and had mean serum troug h levels of 6.88 +/- 2 mu g/ml and 72.04 +/- 45.6 mu g/ml, respectivel y, Dietary calcium intake was similar in control and treated groups, A fter correction for gender and age, children treated with valproate ha d a 14% (p = 0.003) and 10% (p = 0.005) reduction in bone mineral dens ity at the axial and appendicular sites, respectively, The reduction i n bone mineral density increased with the duration of valproate therap y, Carbamazepine did not significantly reduce bone mineral density, Co nclusion: Valproate montherapy, but not carbamazepine therapy, signifi cantly reduces axial and appendicular bone mineral density in children with idiopathic epilepsy and may increase their risk of osteoporotic fractures.