Endocrine Abstracts

Introduction: Anti-epileptic drugs, usually defined according to their effect on the cytochrome P450 system, might lead to bone mineral density (BMD) decrease and fractures. The anticonvulsant valproate is a hepatic enzyme inhibitor, effective in many types of epilepsy. The present study aimed to assess the impact of long-term valproate monotherapy on BMD in a sample of consecutive ambulatory adult patients with epilepsy.

Methods/design: This cross-sectional study recruited 41 consecutive adult epileptic patients receiving valproate monotherapy for at least two years. BMD at the level of the lumbar spine was assessed by dual energy X-ray absorptiometry (DXA). All subjects underwent an evaluation that included serum levels of total calcium, phosphorus, magnesium, 25-hydroxyvitamin D3 and parathormone.

Results: No case of osteoporosis was documented in the sample, while osteopenia was present in 24% of subjects. Duration and dosage of valproate monotherapy did not correlate with any of the T- and Z-scores at the lumbar spine. Dividing patients according to the duration of valproate monotherapy into long- and short-term group resulted in similar findings. In addition, no association was documented between duration or dosage of valproate monotherapy and biochemical parameters.

Conclusion: The present study could not identify any correlation between duration or dosage of valproate monotherapy with BMD measurements in adult patients with epilepsy. No case of osteoporosis was identified in patients treated with valproate for a mean period of more than ten years. These findings provide indirect evidence against a potential detrimental effect of long-term valproate monotherapy on bone metabolism.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: