Hyperlipidemia in patients newly treated with anticonvulsants: A population study.

Objective: To determine the incidence of hyperlipidemia after first anticonvulsant treatment for seizures, using a large US administrative claims database.

Methods: We obtained data from the MarketScan Commercial and Medicare databases for 2005-2009 for all adult patients newly treated with an anticonvulsant for seizures who had no previous history of hyperlipidemia or treatment with a lipid-lowering agent. We divided the population based upon whether they were treated with an enzyme-inducing anticonvulsant (phenytoin, carbamazepine, phenobarbital, primidone) or a noninducing anticonvulsant (all others). The primary outcome measure was a new diagnosis of hyperlipidemia during subsequent follow-up. We accounted for a large number of demographic and clinical covariates.

Results: Of 11 374 subjects, 8778 (77%) were prescribed noninducers and 2596 (23%) were prescribed inducers. New hyperlipidemia diagnoses were seen in 14.6% of the patients started on inducing anticonvulsants and 10.7% of the patients started on noninducing anticonvulsants (P < .001). Both hyperlipidemia and the use of inducers were significantly associated with older age and male gender. After accounting for covariates, inducer prescription was still associated with 23% higher odds of a subsequent diagnosis of hyperlipidemia (odds ratio = 1.225, 95% confidence interval = 1.066-1.408, P < .001).

Significance: The use of enzyme-inducing anticonvulsants in patients with newly diagnosed epilepsy was associated with a significant increase in subsequent diagnoses of hyperlipidemia, suggesting that the lipid-elevating properties of these agents are of genuine clinical importance. This adds to the body of data demonstrating that these agents are likely associated with additional hassle, cost, and morbidity.