New anticonvulsants and bone metabolism

Data on the influence of new anticonvulsants (AED) on bone health are sparse and inhomogeneous. The hope that the newer drugs are superior compared to older anticonvulsants is largely based on the assumption that AED-associated osteoporosis is causally related to hepatic enzyme induction. Studies, which compared enzyme-inducers to non-inducers were however unable to confirm this hypothesis. A major methodological problem of these studies is the inclusion of valproate among the non-inducers, since several studies have suggested that valproate treatment is also associated with an increased risk for osteoporosis - despite the lack of enzyme induction. Existing data with respect to individual new AEDs are insufficient to exclude any substance-specific risks for long-term bone health. In conclusion, systematic studies are needed to demonstrate that newer AEDs are safer with respect to bone health as compared to older AEDs.