ABSTRACT

Long-term usage of antiepileptic drugs is associated with abnormal bone mineral metabolism, osteoporosis and an increased risk of fracture. The main mechanism seems to be focused on vitamin D deficiency that arises from antiepileptics. The primary objective of the present study was to investigate the effects of carbamazepine, valproic acid, oxcarbazepine, levetiracetam and lamotrigine monotherapies on the bone health status of the patients with epilepsy.

This study included 270 patients with epilepsy who underwent carbamazepine (n=75), valproic acid (n=75), oxcarbazepine (n=37), levetiracetam (n=54) or lamotrigine (n=29) monotherapy for at least one year and 71 healthy controls. The demographic and clinical features of the patients were noted. The vitamin D, calcium, ionized calcium and total protein levels of the participants were prospectively evaluated.

Vitamin D deficiency was found as 47.9% in the control group and 78.5% in the patients with epilepsy. The vitamin D levels of the patients taking carbamazepine, valproic acid, oxcarbazepine and levetiracetam were significantly lower than those of the control group. In addition, vitamin D deficiency frequencies in these groups were significantly higher than the control group. A negative correlation was found between the duration of the drug use and vitamin D levels in the valproic acid and levetiracetam groups.

Vitamin D deficiency is common in patients with epilepsy who have long-term use of antiepileptic drugs and may contribute in part to the increased risk of fractures in this population. The findings obtained in this study suggest that the vitamin-D levels of patients with epilepsy should be regularly assessed.

Keywords: Vitamin D deficiency, karbamazepine, lamotrigine, levetiracetam, oxcarbazepine, valproic acid