The Effect of Valproic Acid or Carbamazepine at Bone Metabolism in Epileptic Patients

Objectives: In this study, we evaluated the effects of the chronic use of carbamazepine and valproic acid on the bone metabolism in patients with epilepsy. Methods: We measured serum levels of calcium, phosphorus, alkaline phosphatase, osteocalcin, and urinary deoxypyridinoline in normal controls and in epilepsy patients taking carbamazepine or valproic acid as monotherapy for at least one year. Results: Alkaline phosphatase levels were significantly higher in carbamazepine group when compared to controls. Calcium, phosphorous and osteocalcine levels were significantly elevated in the valproic acid group as compared with controls. Deoxypyridinoline is specific marker of bone resorption and osteoclastic activity which is excreted unmetabolized in urine. Deoxypyridinoline levels did not differ significantly among the patient versus control groups. Conclusion: The most important results of the bone metabolism disorder are osteoporosis, osteomalacia and fractures. The risk of fractures may increase in epilepsy patients on valproic acid treatment, because the bone metabolism is inversely affected from the chronic use of this drug.