Abstracts

Recent studies have shown that some enzyme-inducing antiepileptic drugs (EIAEDs) are associated with osteoporosis and an excess number of fractures. 3A4 is the main CYP450 isoenzyme involved in the degradation of active Vitamin D (Vit D) to its inactive form. It is thought that the primary mechanism of this problem is due to an AED induction of the metabolism of Vit D through the CYP450 system. The potential development of osteoporosis might be prevented by the use of Vit D and calcium (Ca) supplements. It is uncertain as to how to treat the Vit D deficiency in epilepsy patients, who often have been taking AEDs for many years. Although maintenance therapy guidelines for those at high risk for developing osteoporosis exist, a more rapid protocol might be useful to normalize Vit D levels. The objective of this study was to determine if replenishment of 25-hydroxy Vitamin D[sub]3[/sub] (25-OH- D[sub]3[/sub])[sub] [/sub]levels by a 12-week course of weekly high-dose Ergocalciferol, vitamin D[sub]2,[/sub] will normalize the 25-OH- D[sub]3[/sub] levels., The protocol took male patients on AEDs and looked at Vitamin D3, PTH and calcium levels. If the results showed the patient to be deficient in Vitamin D3 ([lt]20 ng/ml with normal iPTH or Vitamin D [lt]30ng/ml and elevated iPTH), then the patient received Ca supplementation with Ergocalciferol (Ergo) 50,000 IU/week for 12 weeks. In addition, all patients were placed on Oscal 500 + D (Ca 500MG/Vitamin D 200 IU) twice daily. Labs were repeated at 16 weeks, and if Vitamin D3 levels were still low, then the 12-week course of Ergo was repeated. 58 patients, mean age 58 and mean duration of AED therapy 23 years, met this criteria., Analysis showed a difference in Vit D, iPTH, and Ca levels before and after treatment with Ergo. However, only the change in Vit D levels was significant. We further divided into subgroups of EIAEDs, NEIAEDs, and valproic acid (VPA) examining Vit D only., Patients that took a 12-week course of Ergo had a significant increase in 25-OH- D[sub]3 [/sub]levels. Although iPTH trended down and Ca levels increased after Ergo treatment, there was no significant effect seen between the before and after treatment group. Long term follow-up of these labs in this study group is needed to correlate whether the increase in Vit D will decrease the rate of osteoporosis.[table1],