Is it safe to switch from a name brand epilepsy medication to its generic version?

Answers from Joseph Sirven, M.D.

A name brand and generic medication can usually be safely substituted for each other, but epilepsy medications might be different. Patient and doctor surveys and several small studies have reported that switching from a name brand epilepsy medication to its generic equivalent could cause an increase of seizures and other side effects.

Manufacturers' formulations of name brand and generic equivalents sometimes have small variances in composition. But the Food and Drug Administration (FDA) attempts to ensure that generic medications are similar in effectiveness to name brand medications. According to the FDA, a manufacturer must submit data showing that in a small sample of healthy adults, a generic drug "delivers the same amount of active ingredients into a person's bloodstream in the same amount of time as the brand-name drug." However, some argue that this doesn't necessarily mean that a generic epilepsy drug has been proved to produce the same effects in all people. And the American Academy of Neurology and the Epilepsy Foundation report that even slight differences between epilepsy medications, even those within the FDA's acceptable range, could cause harmful effects.

To complicate things, other factors also influence the effectiveness of an epilepsy medication, including other medications, herbal supplements, alcohol and dietary changes. So it's unclear whether changes in a medication's effectiveness might be due to a medication switch or to some other consideration.

It's good to be cautious. Don't switch epilepsy medications — or brands — before talking to your doctor. Keep in mind that if you have prescription drug coverage, the plan may not pay for a name brand medication if a generic is available. So the pharmacist may give you the generic medication unless your doctor indicates not to substitute a name brand drug.

You have the final say as to whether you buy the name brand or generic medication, so ask your doctor if switching medication is safe and acceptable. Then, check your medication carefully before leaving the pharmacy.


Joseph Sirven, M.D.

Sep. 17, 2009