Risk of oral birth defects in infants born to women treated with topiramate (Topamax®)

Johnson & Johnson Pte Ltd, in consultation with HSA, is informing healthcare professionals of new evidence suggesting an increase in the risk of oral birth defects in infants born to women treated with topiramate monotherapy during pregnancy. Data from the North American Antiepileptic Drug (NAAED) Pregnancy Registry indicated that the prevalence of oral clefts was 1.2% in infants exposed to topiramate in utero as compared to a prevalence of 0.39% to 0.46% in infants exposed to other AEDs. Relative risk of oral clefts in topiramate-exposed pregnancies in the NAAED Pregnancy Registry was 9.6 (95%CI: 3.6-25.7) when compared to background risk in the population. The UK Epilepsy and Pregnancy Register reported a similar increased prevalence of oral clefts (3.2 %) among infants exposed to topiramate monotherapy in utero which translates to a 16-fold increase in risk of oral clefts in topiramate-exposed pregnancies as compared to the background incidence (0.2%). With this new information, topiramate has been reclassified from Pregnancy Category C to D by the US Food and Drug Administration. The local package insert will be strengthened to include the safety information and healthcare providers are advised to weigh the benefits and risks of Topamax® when prescribing it to women of childbearing potential, including the need to emphasise the importance of using an effective birth control.