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
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
"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
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.