Concerns about Topamax Side Effects Raised

Houston, TXWhile concerns have been raised about the risk of Topamax side effects, especially the risk of Topamax side effects in children, a recent study has failed to find similar risks in newer antiepileptic medications. That could mean that newer drugs may be safer to use during pregnancy than Topamax, although researchers reportedly did not find evidence of a risk of major birth defects in infants exposed to Topamax. The US Food and Drug Administration (FDA), however, has issued a warning about the risks associated with exposing a fetus to Topamax.

A Danish study, published in the Journal of the American Medical Association (JAMA; 05/11), examined the risk of birth defects in infants exposed during the first trimester to newer-generation antiepileptic medications, including lamotrigine, oxcarbazepine and topiramate (the generic name for Topamax). Research showed that just over three percent of infants exposed to the antiepileptic medications during the first trimester were diagnosed with a major birth defect. That is compared to approximately two-and-a-half percent of infants who were not exposed to an antiepileptic medication prior to birth being diagnosed with a major birth defect.

The findings led researchers to conclude that first-trimester exposure to the medications, when compared with no exposure, "was not associated with an increased risk of major birth defects."

The FDA, however, recently issued a warning, alerting patients to the risk of birth defects in infants exposed to Topamax. Specifically, the FDA warned about the risk of oral cleft (including cleft lip and/or cleft palate) when newborns were exposed to Topamax prior to birth.

The agency's safety announcement (03/04/11) noted that oral clefts develop during the first trimester, before many women even know they are pregnant. As a result, the benefits and risks of the medication should be carefully considered when women of childbearing age are prescribed Topiramate.

Furthermore, Topiramate was moved from Pregnancy Category C to Pregnancy Category D, indicating that there is evidence of human fetal risk based on human data.

The FDA's announcement came after information from the North American Antiepileptic Drug (NAAED) Pregnancy Registry indicated the risk of an oral cleft in infants exposed to Topiramate during the first trimester was 1.4 percent, compared with between 0.38 percent and 0.55 percent in infants exposed to other antiepileptic medications. Infants not exposed to any epileptic medications had a 0.07 percent prevalence of oral cleft.