Often, the Food and Drug Administration approves drugs after trials with a few thousand users only to see problems emerge later when the drug reaches the general market.
It happened with the pain medication Vioxx, and it might be happening now with the hormonal patch for birth control, Ortho Evra.
The FDA should require a large, rigorous controlled study of the patch to make sure that it is, at a minimum, no more likely to cause life-threatening blood clots than the birth control pill.
Specialists in women’s health have long been alert to the danger of blood clots caused by the hormones in birth control pills. Statistically the risk is small, but enough to prompt warnings for women who smoke or have a personal or family history of clotting or other cardiovascular problems. Birth control patches come with similar warnings. A recent survey by the Associated Press of reports of patch-related problems to the Food and Drug Administration raises the possibility that the threat of clotting with the patch, while still slight, is greater than with the pill.
According to the AP, which filed a Freedom of Information Act request to obtain reports of adverse events from the FDA, the risk of death with the patch could be about three times greater than with the pill. The news agency found that there were 12 clot-related deaths among the approximately 800,000 users of the patch in 2004. The FDA first approved the Ortho Evra patch in 2001.
The patch’s maker, Ortho-McNeil, said its product is as safe as the pill and that AP exaggerated the risk by using too low a number of patch users in 2004. The company said it is doing an epidemiological study of the patch and its side effects.
The AP’s review did not establish a causal link between the deaths and the patch. Moreover, the data might be distorted by a tendency of healthcare providers to report adverse events associated with a drug more readily when it is new to the market. Also, in the first months or years of use, the patch is likely to attract women who have experienced problems with the pill, which could further skew results.
These flaws are inherent in the passive system of reports to the FDA by doctors, consumers, and manufacturers. They provide a strong argument for a requirement by the FDA that the manufacturer of any new drug that is know to have serious side effects conduct a substantial postrelease study of its safety.
In a letter Tuesday to the FDA supporting the idea, Amy Allina of the Washington-based National Women’s Health Collective said that, even if such a study did not establish causality, ”it could give women a much better idea of the rate at which the problem is occurring.” According to the AP, such a study was recommended by an FDA medical reviewer at the time the patch was approved, but the FDA did not mandate one. It should now.