Disturbed calcium-vitamin D metabolism in patients on anti-epileptic drugs

Introduction: Epilepsy is a common chronic neurological disorder, usually requiring long term treatment with anti-epileptic drugs (AEDs). There is paucity in data in relation to the effect of AED on calcium metabolism in North India. In view of this the present study was undertaken to assess the effect of AED on calcium metabolism. Methods: The present cross-sectional study included epileptic patients of both sex attending the neurology OPD & IPD clinics. Patients were divided into three groups: - group1 included patients on monotherapy receiving 1 AED, group 2 on dual therapy receiving 2 AED and group 3 patients on polytherapy receiving>2 AED. Serum analysis of total calcium, phosphorus, alkaline phosphorus, ionised calcium & vitamin D levels were conducted. The data between the groups was analyzed by using 1 way analysis of variance (ANOVA). Results: The study included 150 patients in which 50 patients each belonged to groups1, 2 and 3 respectively. 60% patients were male. 86 patients had generalised epilepsy and 64 suffered from partial seizures. 42% of the patients were on AED treatment for>5 years. Serum levels of calcium and vitamin D were significantly decreased (p=.000 and p>0.05 respectively) in the polytherapy group in comparison to the mono and dual therapy groups. On the other hand, alkaline phosphatase & phosphorus levels were significantly increased in the polytherapy group (p=.000). Conclusion: Hypovitaminosis was commonly observed in the patients on AED, even at sub-therapeutic serum levels of the drug.