Adverse effects of antiepileptic drugs on bone mineral density.

The aim of this study is to determine the frequency of changes in biochemical markers of bone metabolism in children who are receiving valproic acid, carbamazepine, and oxcarbazepine. Thirty healthy children and 68 children with idiopathic epilepsy treated with either carbamazepine (n = 23), valproic acid (n = 31), or oxcarbazepine (n = 14) for more than 1 year were enrolled into the study. Blood samples were obtained in order to determine biochemical parameters (calcium, phosphorus, alkaline phosphates, parathormone, and 25-hydroxyvitamin D). Bone mineral density was measured with the dual-energy x-ray absorptiometry method. There were no significant differences in the serum concentrations of calcium, phosphorus, aspartate aminotransferase, alanine aminotransferase, and albumin levels between the four groups. However, serum alkaline phosphatase concentrations were higher in the patient group as compared with the control subjects. In patients receiving antiepileptic drugs, bone mineral density values were significantly lower than the healthy control group. In conclusion, long-term antiepileptic drug treatment either with valproic acid, carbamazepine, or with oxcarbazepine which has unknown effects on skeletal mineralization, induces a state of decreased bone mineral density.