Abstracts

There are evidences suggesting that antiepileptic drugs (AEDs) may contribute to decrease bone mineral density (BMD) and, consequently, to increase the risk of osteoporosis and fractures. Previous published studies, however, analyzed only the effect of some AEDs, comparing few drugs to each other, and very few times making a comparison with a control group.
A cross [ndash] section study was performed on 147 adults (age range 18-45): 77 were epileptic patients on AEDs therapy for at least 12 months, and 70 healthy control subjects matched for age, sex, weight and height. Body composition and BMD were assessed with dual-energy x-ray absorptiometry. A detailed questionnaire assessing calcium intake, physical activity and light exposure was administered to all patients and controls. Vit. D concentration was measured only during the same period of the year (winter).
About 35% of epileptic patients showed BMD changes indicative of osteopenia or osteoporosis. Statistical analysis with Bonferroni /Dunn post-hoc test revealed that carbamazepine, phenobarbital, phenytoin, and valproate caused a significant decrease in BMD in comparison to normal individuals. The new AEDs such as topiramate, lamotrigine and levetiracetam seemed not to affect bone mineral density. None of healthy subjects had osteoporosis or osteopenia. On the other hand, there were no differences in body composition (fat mass, lean mass) and vit. D levels between epileptic patients and healthy individuals.
The results of this study support the idea that some AEDs, especially the enzyme-inducing drugs, are risk factor for early low bone density, irrespective of vitamine D levels. At-risk patients for bone loss should be screened early by BMD monitoring with dual energy x-ray absorptiometry of total and spine bone mineral density.