Antiseizure Drug Depakote Under Fire
Evidence Linking Depakote to Birth Defects Is Mounting
Dec. 7, 2004 - The antiseizure drug Depakote has been linked to birth defects and lower IQs among children exposed to it in the womb, but millions of American women may be taking it without knowing the risks, a group of epilepsy experts warned Tuesday.
Officials with the Epilepsy Foundation and the American Epilepsy Society said as many as 15 million prescriptions for antiseizure drugs are written each year to women in their childbearing years. The drugs are commonly used to treat migraine headaches and bipolar disorder in addition to epilepsy.
Depakote is one of the most widely prescribed antiseizure drugs. In one ongoing study, one in four children born to mothers who took the drug during pregnancy experienced serious adverse events including birth defects and developmental delays. That compared to an adverse event rate of around 10% in children exposed in the womb to the antiseizure drug Tegretol and a 1% adverse event rate among children exposed to the drug Lamictal.
"While our study is not definitive, it certainly raises serious concerns," principal investigator Kimford J. Meador, MD, said at a news conference on Tuesday. The briefing was held at the American Epilepsy Society's annual meeting in New Orleans.
Meador said six other studies and national registries of antiseizure drug users found that the highest rate of birth defects occurred among children born to Depakote users. He added that the clinical evidence is strong enough to argue against the drug's use as an initial treatment for women who might become pregnant.
"That is not to say that [Depakote] shouldn't be used by these women at all," he said, adding that the drug may be the only option for some women since it is often prescribed for the most hard-to-control seizures.
Getting the Answers
In addition to Depakote, there are increasing concerns about the safety of the barbiturate phenobarbital, which is also used to control seizures. The panel of experts said these two drugs are the most "worrisome" of the large group of medications used in the treatment of epilepsy, but they added that the safety of most other drugs is not known.
Studies do suggest that the risk of birth defects and mental problems among babies born to women taking Lamictal is no greater than among the general population of pregnant women. Lamictal manufacturer GlaxoSmithKline sponsored Tuesday's news briefing. GlaxoSmithKline is a WebMD sponsor.
The news conference was held, in part, to urge pregnant women on antiseizure drugs to participate in a national registry designed to clarify the risks and benefits of the medications. So far, 4,000 women taking 21 different medications have enrolled in the North American Antiepileptic Drug Pregnancy Registry, but conference organizers said much larger numbers are needed to get the answers they need.