Switching between A-rated anti-epileptic drug formulations does not increase seizure risk

Express Scripts, Inc. (Nasdaq: ESRX), one of the largest pharmacy benefit management companies in North America, announced today results of a study that examined the association of seizure risk among epilepsy patients after switching between A-rated anti-epileptic drug formulations. The study found no evidence that switching between A-rated anti-epileptic drugs, including brand to generic substitution, was associated with increased emergency room visits or hospitalizations for epilepsy.

The claims-based case-control study, conducted by Express Scripts, is the most comprehensive research to date of switching between A-rated anti-epileptic drugs. The research was designed to address methodological limitations of previous studies, and uses the largest sample size over the longest time frame of any study to date.

The results are available on-line and will be published in the February 2010 issue of Current Medical Research and Opinion (http://www.cmrojournal.com).

Concerns about switching between A-rated anti-epileptic drugs surfaced in the healthcare community after earlier findings suggested an association between anti-epileptic drug switching, particularly to lower-cost generic medications, and seizure activity. Anti-epileptic drugs are considered "narrow therapeutic index" drugs, thus it is thought that small deviations in blood concentrations can result in changes in the safety and effectiveness of the drug. In November, the U.S. Food and Drug Administration commissioned the National Institutes of Health to conduct studies that will provide definitive evidence around this issue.

"Rigorous research methodology is fundamental to making the right healthcare decisions. These results hold important implications for physicians, patients and plan sponsors as we all work toward optimizing health outcomes at the lowest cost," said Dr. Steven Miller, Chief Medical Officer for Express Scripts. "Given that many anti-epileptic drugs are now available in lower cost generic formulations, understanding the impact of switching is a critical question to answer."

The information uncovered in the study supports the position of Express Scripts in suggesting the use of generic anti-epileptic drugs as a safe and effective cost-saving option for patients and clients seeking to reduce medication-related waste.

Express Scripts and HealthCore, a subsidiary of WellPoint, Inc., have plans to collaborate on further research in this and other areas to improve overall patient health through the safe and effective use of prescription medications.