Fracture risk with use of liver enzyme inducing antiepileptic drugs in people with active epilepsy: cohort study using the general practice research database.

PURPOSE: Liver enzyme inducing antiepileptic drugs (LEI AEDs) have adverse effects on bone metabolism but it is unclear whether this translates into increased fracture risk. This population based cohort study aimed to evaluate whether treatment with LEI AEDs is associated with increased risk of fracture in people with active epilepsy. METHODS: The cohort included patients diagnosed with epilepsy and prescribed AEDs while registered at a GPRD general practice during 1993-2008. The hazard ratio with current use of LEI AEDs for fracture at any site and hip fracture was estimated using Cox proportional hazards models. RESULTS: There were 7356 fractures (788 hip fractures) in 63259 participants. In women, the adjusted hazard ratio with use of LEI AEDs was 1.22 for fracture (95% CI 1.12-1.34; p