Another Problem with an FDA Approved Drug – Topamax

The FDA adds an additional warning on the seizure and migraine headache medication Topamax related to birth defects.

Topamax, also known as topiramate in its generic version, is a seizure , epilepsy and migraine headache medication that has been on the market since 1996. This drug, developed by Ortho McNeil Janssen, and ultimately marketed by Johnson and Johnson, was the thirteenth best selling prescription drug in 2008 with annual U.S sales of about $2.4 billion.

Recent studies have shown that Topamax may be associated with increased risk of major malformations in newborns including cleft palate. This new data was sufficient to cause the FDA to issue a change in warnings for Topamax on March 4, 2011 suggesting that doctors warn all women of childbearing age of the dangers of taking Topamax while pregnant and suggesting that doctors seek other medication with less risk for pregnant women.

As always, the question is why does it take so long for these warnings to come out? Topamax was on the market 14 years before this warning and had run though its entire patent cycle before patients were warned of the risk to their babies. With annual sales of $2.4 billion, many many women must have been taking it. In its pre-approval testing, Topamax/topiramate had caused fetal malformations in laboratory animals. Despite this warning signal, post marketing surveillance did not reveal trouble until 2011. The manufacturer, who is getting the profit, has the clear responsibility to be vigilant in finding signals of health problems once a drug is on the market. With the warning from the animal studies, its seems absurd that this took so long and caused possibly hundreds of children to be born with cleft palate. Instead of prevention, patients must look to their lawyers to seek justice for this oversight.

Sooner or later it will occur to the pharmaceutical industry to set up programs to detect rare but serious side effects in all drugs.