Mechanisms of Decreased Bone Mineral Density and Altered Bone Metabolism Induced by Antiepileptic Drugs

J Korean Neurol Assoc > Volume 23(6); 2005 > Article

Journal of the Korean Neurological Association 2005;23(6): 758-764.

항경련제에 의한 골밀도 감소와 골대사 변화의 기전

김숙희, 이향운 이진화 김용재 최경규 정혜원a 강은숙b

이화여자대학교 의과대학 신경과학교실, 산부인과학교실a, 진단검사의학과b, 의과학연구소

Mechanisms of Decreased Bone Mineral Density and Altered Bone Metabolism Induced by Antiepileptic Drugs

Sook Hui Kim

Departments of Neurology, Obstetrics and Gynecologya, Laboratory Medicineb, College of Medicine, Ewha Womans University and Ewha Medical Research Institute, Seoul, Korea

Abstract

Background: The adverse effects of antiepileptic drugs (AEDs) on bone metabolism have been reported in epilepsy patients, however the underlying mechanisms have yet to be completely understood. The purpose of this study was to determine whether or not there is an abnormality in bone mineral density (BMD) in epilepsy patients with long-term AED treatment, and also to investigate the underlying mechanisms related to those abnormalities.
Methods: BMD was measured by densitometer using dual-energy X-ray absorptionmetry (Lunar PIXI) at the right calcaneus in both patients who had already taken AEDs longer than 6 months, and in patients with newly diagnosed epilepsy. A total of 80 patients (45 women and 35 men) were recruited for the former group, and 29 (11 women and 18 men) for the latter group. In the latter group, BMD and markers for bone metabolism were measured before and after 6 months of AED treatment including serum parathyroid hormone (PTH), total and ionized calcium, osteocalcin, 25-(OH) vitamin D, and urine pyrilinks.
Results: BMD decreased in epileptic women compared to the control group (p=0.021). Decreased BMD was most prominent in patients with phenytoin or phenobarbital. Osteocalcin and PTH levels increased after 6 months of AED therapy (p=0.002 and p<0.0001, respectively).
Conclusions: BMD decreased in patients with epilepsy, especially in women even in premenopausal age, in those who are taking phenytoin or phenobarbital. AEDs increase bone turnover, which may relate to these alterations in bone mass and bone metabolism. KeyWords:Antiepileptic drugs, Bone mineral density, Bone metabolism, Osteoporosis, Bone turnover