Evaluation of bone mineral metabolism in children receiving carbamazepine and valproic acid

Dual energy X-ray absorptiometry (DXA) was used to assess lumbar spine (L2- 4) and femoral neck bone mineral density (BMD) in 36 children taking either carbamazepine or valproic acid for longer than one year, for generalized i diopathic epilepsy. Patients were matched with controls. Biochemical parame ters of bone mineral metabolism were also measured. BMD values at both the femur neck and lumbar spine in both the carbamazepine and valproic acid gro ups were not significantly different from that of the control group. Serum levels of calcium were subnormal and alkaline phosphatase levels were high in the carbamazepine group. Urinary calcium levels were significantly lower in broth groups than in the control group (p less than or equal to 0.05) a nd also significantly lower in the valproic acid group than in the carbamaz epine group (p less than or equal to 0.05), There were no other significant biochemical changes in either group. In conclusion, the results suggest th at valproic acid and carbamazepine monotherapies have minimal effects on bo ne mineral metabolism, but routine monitoring of risk and consideration of prophylactic vitamin D supplementation is important.