Topamax, is the antiepileptic drug that has been shown to cause oral clefts in infants whose mothers took the drug while pregnant and may actually increase a woman’s chance of becoming pregnant.
According to Topamax’s label, the drug may reduce the effectiveness of oral contraceptives. Topamax use can lead to the development of a cleft lip or cleft palate during the first trimester of pregnancy, often before many women are aware that they are pregnant. Cleft lip and cleft palate are craniofacial birth defects that are the result of the improper formation of a child’s upper lip or palate during fetal development. Oral clefts continue to cause complications throughout life including feeding difficulties, ear infections, hearing loss, dental problems, and speech and language delays.
Studies have also shown that Topamax reduces the effectiveness of birth control pills when it is used in combination with valproic acid, an anticonvulsant drug also used for the treatment of epilepsy. When taken with valproic acid, Topamax decreases the body’s expose to ethinyl estradiol, a form of estrogen used in oral contraceptives.
Data collected from the North American Antiepileptic Drug (NAAED) Pregnancy Registry shows a 1.4% incidence of oral clefts in infants whose mothers were treated with Topamax during the first trimester, compared to 0.07% in infants of mothers who were not treated with antiepileptic drugs.
Because of the risk of birth defects associated with Topamax use, the FDA urges doctors to discuss birth control with their female patients. If a woman discovers she has become pregnant while taking Topamax, she should contact her doctor immediately.