Epilepsy Medications: When Is It Safe to Substitute a Generic?

The FDA says generic epilepsy drugs are no different from generic drugs for other conditions: virtually identical to brand-name drugs in their effects. Therefore, there's no problem substituting generic drugs for epilepsy.

But many doctors who specialize in treating epilepsy don't agree. For a small minority of patients, they say, generic drugs may be less effective at controlling seizures. Disturbed by seeing people develop seizures soon after changing to generic drugs, many epilepsy doctors are questioning the FDA's position.

"There are enough anecdotes to be of concern," says Shlomo Shinnar, MD, spokesman for the American Academy of Neurology. "Until we're sure there's no problem, no substitutions should occur without a decision by the patient and the physician."

But sometimes that's not as easy as it sounds. For instance, to cut costs, some insurance companies may automatically convert some prescriptions from brand to generic epilepsy drugs at the pharmacy. Or the price difference between brands and generics is so large, people with epilepsy are effectively forced into a switch to generic drugs.

The standoff pits insurance companies, health plans, and pharmacies against doctors and people living with epilepsy. Although experts believe relatively few people with epilepsy are vulnerable, "for some of them, a new seizure can be a threat to their livelihood, or even their life," says Shinnar.

Generic Epilepsy Drugs: Does a Problem Exist?

The FDA tightly regulates manufacture of all generic drugs, just like brand-name drugs. Epilepsy drugs are held to the same high standards:

• Generic epilepsy drugs have precisely the same amount of drug as the brand-name version.
• Generic drugs must meet the same high standards for purity, quality, and strength as the drugs they imitate.
• In reviews done by the FDA, generic drugs achieve almost exactly the blood levels as brand-names -- with only a 3% to 4% difference.

With generic and brand-name epilepsy drugs so similar, how could there be a problem with generic drugs? Experts believe that whatever problem with generic drugs exists, it doesn't affect most people with epilepsy.

"For the vast majority of patients, there probably isn't a problem with switching to a generic," says Jacqueline French, MD, professor of neurology at New York University's school of medicine. "But some people are on relatively thin ice when it comes to seizure control. They're sensitive to small changes in blood levels" of their epilepsy drugs, she says.

Potential Problems With Generic Epilepsy Drugs

There may be several ways switching to generic epilepsy drugs could cause potential problems, experts say. Many epilepsy drugs are absorbed and metabolized in more complex ways than other drugs. Researchers argue that although the differences in generics allowed by the FDA do not affect treatment for most conditions, the differences could have a negative impact for treating epilepsy.