Epilepsy Medications: When Is It Safe to Substitute a Generic?
Potential Problems With Generic Epilepsy Drugs continued...
Experts are quick to concede that their collective stories and experience "are cause for concern, but it's not evidence," according to Alan Ettinger, MD, professor of clinical neurology at the Albert Einstein College of Medicine. "What's needed are well-designed clinical trials to settle the issue."
Studies on switching of epilepsy drugs have so far been limited, but they, too, hint at a possible problem.
- In a Canadian study from 2007, more than one-quarter of people switching to generic Lamictal switched back to the brand-name drug within three years. People taking generics averaged one more visit to the doctor each year. And among people who were hospitalized, those taking generic epilepsy drugs stayed in the hospital slightly longer.
- In a 2008 study of people with breakthrough seizures after a switch to generic drugs, blood levels of epilepsy drugs were compared before and after the switch. Half the people with seizures had lower blood levels of the generic drugs.
But many doctors treating epilepsy today are unwilling to wait years for clinical trials to provide answers. Based on lab studies and their own experience managing epilepsy, they're raising a caution flag over switching to generic drugs.
"Yes, I think there's a real problem, although we don't know the magnitude of it right now," says Steven Schachter, MD, professor of neurology at Harvard Medical School. "I think we all need to use caution with generic substitution until all the facts are in."
Almost 90% of physicians recently surveyed agree a problem exists, according to a leading epilepsy journal. Further, two-thirds of doctors treating epilepsy linked new seizures in their own patients with a switch to generic drugs.
Responding to its members' concerns, the American Academy of Neurology issued a position statement in 2007 speaking out against forced switching to generic drugs for epilepsy. Leading epilepsy advocacy groups take the same stance.
No Evidence, No Action, Says FDA
So far, the controversy has not spurred the FDA to make a change. Citing the lack of good evidence to the contrary, FDA's position remains that generic epilepsy drugs are, for all intents and purposes, identical to their branded counterparts. Generic substitution, even monthly, shouldn't cause breakthrough seizures or other side effects.
Officials suggest that seizures don't really increase after a switch to generic drugs; rather, they say doctors and patients are more likely to recognize seizures during this time, and wrongly blame the generic epilepsy drug. Lacking good data either way, the FDA encourages doctors to report problems related to switching to generic drugs to its web site.