Epilepsy: fractures and the role of cumulative antiepileptic drug load
Version of Record online: 21 MAR 2011
© 2011 John Wiley & Sons A/S
Acta Neurologica Scandinavica
Volume 125, Issue 1, pages 54–59, January 2012
How to Cite
Beerhorst, K., Schouwenaars, F. M., Tan, I. Y. and Aldenkamp, A. P. (2012), Epilepsy: fractures and the role of cumulative antiepileptic drug load. Acta Neurologica Scandinavica, 125: 54–59. doi: 10.1111/j.1600-0404.2011.01509.x
- Issue online: 21 DEC 2011
- Version of Record online: 21 MAR 2011
- Accepted for publication February 11, 2011
- antiepileptic drugs;
- bone mineral density;
- cumulative drug load;
Beerhorst K, Schouwenaars FM, Tan IY, Aldenkamp AP. Epilepsy: fractures and the role of cumulative antiepileptic drug load. Acta Neurol Scand: 2012: 125: 54–59. © 2011 John Wiley & Sons A/S.
Background– An association between antiepileptic drugs (AEDs), low bone mineral density (BMD), fractures, and abnormalities in bone metabolism has been suggested for a longer period, although conclusive evidence has not been reported. We aimed at studying patient characteristics in a high-risk population. Methods – All adult patients from a residential unit of a tertiary epilepsy center who were diagnosed with osteoporosis and consequently treated with a bisphosphonate at that moment were included. Correlations between reported fractures and patient characteristics were explored. Results – Of the total population of 261 adult patients, 54 patients were included resulting in a high prevalence rate of 21% osteoporosis in this population. The number of fractures correlated significantly with ambulatory status (r = −0.269, P = 0.05), drug load (r = 0.286, P = 0.04), and current number of AEDs (r = 0.283, P = 0.04). Correlations could not be provided for individual drugs in our population as only a minority was on monotherapy and even less patients had always been on monotherapy of the same antiepileptic drug. Linear regression analysis showed that cumulative drug load (defined by a surrogate parameter: the total duration of epilepsy multiplied by the number of AEDs) was the dominant factor explaining the occurrence of fractures. Conclusion – In this high-risk population, we obtained a positive and strong correlation between the occurrence of fractures in a diagnosed population with osteoporosis and the cumulative drug load of AEDs. This effect seems general, independent of the type of AEDs that were used.