Anti-Seizure Drugs Linked to Osteoporosis Risk: New Study Reveals a Preventive Care Gap

Adults who take certain anti-seizure drugs may be more likely to be diagnosed with decreased bone density, according to a new study by a Carle Illinois College of Medicine research team. The researchers also found that only a fraction of patients on anti-seizure drugs receive supplemental vitamin D to keep bones healthier.

Third-year medical student and lead author Mehreen Ali examined approximately 16,000 patient records from the National Institutes of Health ‘All of Us’ research database. She found that adults taking enzyme-inducing anti-seizure drugs (ASDs) such as carbamazepine, phenytoin, or oxcarbazepine were about 50% more likely to be diagnosed with osteoporosis (a condition that causes bones to weaken or become brittle and more prone to fracture) or osteopenia (bone density loss). 

People taking other types of anti-epilepsy drugs such as levetiracetam, lamotrigine, topiramate, gabapentin, lacosamide, and valproate also had an increased incidence of these conditions, but the risks appear lower than with enzyme-inducing ASDs.

Enzyme-inducing ASDs activate liver proteins that accelerate vitamin D breakdown. Vitamin D helps the body absorb calcium and maintain strong bones.

“What’s most striking about this finding is not the bone disease risk itself — we expected that — but how few patients were receiving vitamin D supplementation, suggesting there is a significant gap in what guidelines recommend and what is actually happening in clinical practices,” Ali said. “This suggests bone-health prevention may be overlooked for many people taking these medications.”

Researchers documented vitamin D supplementation in 20.7% of people taking enzyme-inducing medications and 16.2% of those taking other ASDs. The findings were drawn from prescriptions noted in electronic health records from patients, so they may not capture supplementation by patients who take over-the-counter vitamin D on their own. This also means clinicians have no reliable way to confirm whether patients are taking it.

Ali says the findings highlight the need for more routine attention to vitamin D and bone health among people taking ASDs starting at the time the medication is prescribed.

“This work underscores the importance of understanding the long-term health consequences of epilepsy treatment so that clinicians can make safer treatment decisions and improve lifelong health for people living with epilepsy,” said Dr. Daniel Llano, senior author of the study and a professor of biomedical and translational sciences at Carle Illinois.

Editor’s note: The study findings were presented at the 151^st Annual Meeting of the American Neurological Association (ANA). The research is titled, “The Bone Toll of Epilepsy Treatment: Antiepileptic Drugs, Incident Bone Disease, and a Population-Level Vitamin D Supplementation Gap in 16,769 Adults.”