October 5, 2006

FDA Adds Warning to Patch

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The Food and Drug Administration recently updated the label of the contraceptive patch to include a warning about an increased risk of venous thromboembolism (VTE), blood clots in the veins or pulmonary track.

The birth control patch, also known as Ortho Evra, is simply a one-and-three-quarter-inch square patch that is applied to the skin, where it releases the hormones estrogen and progesterone. The hormones enter the bloodstream and act to prevent ovulation and hence, deter pregnancy.

Women apply one patch a week for three weeks. Unless a woman delays the application or removes the patch too early, the patch is about 99% effective in defending against pregnancy.

Alternatives to the patch include the pill, the ring and the shot. Most popular is the birth control pill, taken once a day for three weeks at a specific time. It too releases estrogen and progesterone to prevent ovulation and also thickens the mucus around the cervix to make it more difficult for sperm to enter the uterus. Some women prefer the patch to the pill since they do not have to remember to apply the patch once a day.

In reaction to the new label update, students using the birth control patch seem to be considering alternative options. However, while some admitted that the results might convince them to switch to the pill, none interviewed said they would stop taking birth control.

“The warnings wouldn’t stop me from taking birth control, but I wouldn’t ever willingly increase the risk of using the patch instead of the pill. If the only advantage is the convenience, I’d rather remember to take a pill every day than have a higher chance of getting a blood clot,” said Emily Jayne ’09.

Estrogen and progesterone promote blood coagulation, which can lead to blood clots. According to the FDA, the patch exposes young women to about 60% more estrogen than does the typical birth control pill (35 micrograms of estrogen).

However, the peak blood levels of estrogen in Ortho Evra are actually 25% lower than typical birth control pills. The estrogen level with the patch is also more constant for the week, while peak blood levels with the pill rapidly rise high and fall low. It is not currently known if peak concentration or total dose absorbed is more conclusive for blood clot risk.

Nevertheless, the patch has been deemed more risky. Whereas the pill must be digested before estrogen enters the bloodstream, the patch sends estrogen directly to the bloodstream. This direct diffusion may be linked to the formation of blood clots, which may lead to serious harm or even death.

The FDA based their label update on two specific studies conducted this year that investigated hormone levels and blood clots in women either on the patch or on the pill.

The first study was supported by a grant from Johnson & Johnson Pharmaceutical Research and Development. The data was acquired through a US-based longitudinal database, which contains information on about 55 million people, called PharMetrics. The study compared the risk of nonfatal VTE in women, aged 15 to 44, using the patch to that of using the pill. The study found that the risk of blood clots was the same with the patch and with an oral contraceptive of 35 micrograms of estrogen.

The second study, though, funded by Ortho Evra and currently unpublished, revealed a two-fold increase in the risk of forming blood clots while on the patch than on the pill.

However, Gannett asserts that Cornellians should not be concerned. The new FDA warning is based upon two studies with conflicting results.

Additionally, their method of data acquisition precluded researchers from investigating whether or not the women who filled prescriptions for the birth control actually ended up taking it.

According to Dr. Alexandra Hall, physician of general medicine and women’s health at Gannett, the data for an increased risk is not yet conclusive. Hall cites two specific studies done, one by the makers of Nuva Ring and one by the makers of Ortho-Evra, as examples. The two studies each used less than 35 patients to collect data and showed of vastly different amounts of total estrogen doses in the pill and patch.

Hall wants students to know the statistics. The overall mortality risk attributed to the effects of hormonal contraception is 1 in 200,000. There is a greater chance of dying from complications in an unplanned pregnancy while using condoms (1 in 76,900).

“You need to look at relative risk versus absolute risk,” said Hall. “Even if there’s a two-fold increase, the risk only goes from being 1 in 200,000 to 2 in 200,000. You have to ask, ‘What does a doubled increase mean?’”

There is also a greater risk of thromboembolic disease while pregnant (1 in 885) than while on birth control (1 in 3000), meaning it is safer to be on the patch than to risk getting an unintended pregnancy, in terms of blood clots, that is.

The data and studies are essentially inconclusive, but the allegedly increased risk is highly publicized.

Sharon Dittmann, associate director for community relations at Gannett, raised the question of spin.

With television news programs focused on ratings, using commercials declaring an increased risk of VTE while on the patch is an effective way of attracting viewers.

There is also a question of political motives behind the new attention.
Pauli Evanson ’09 said, “Since there hasn’t been a lot of conclusive studies done, this shouldn’t dissuade women from using birth control, specifically the patch.”

Gannett encourages students to come in and talk about their concerns.

“We want girls to know they need to talk to us about it,” said Dittman.
Hall emphasized, “What we worry about is girls will rip off the patch and not come to see us. Pregnancy is much more dangerous, and the mortality rate is higher.”

The contraceptive patch was developed by the R.W. Johnson Pharmaceutical Research Institute and is marketed by Ortho-McNeil Pharmaceuticals. Ortho McNeil Pharmaceuticals continues to conduct additional studies investigating the risk of serious blood clots in women using the patch versus the pill.

The patch is definitely not for everyone. Women who smoke, have high blood pressure, diabetes, high cholesterol and/or a medical history relating to blood or organ problems are advised not to use the patch.

Possible side-effects include irregular menstrual bleeding, nausea, weight gain, headaches, skin reactions, dizziness, problems with contact lens use, breast tenderness and blood clots. However, these effects are rare in non-smoking women under 35 with a healthy medical history.