Study shows elevated risk of blood clots in women taking birth control containing drospirenone

October 18, 2012

A U.S. Food and Drug Administration-funded study led by the Kaiser Permanente Northern California Division of Research found an increased risk of arterial thrombotic events (ATE) and venous thromboembolic events (VTE)—commonly referred to as blockage of arteries and blood clots, respectively—associated with drospirenone-containing birth control pills compared to four low-dose estrogen combined hormonal contraceptives.

The study appears in the current online issue of Contraception.

"We found that starting use of -containing combined hormonal was associated with a 77 percent increase in the risk of hospitalization for VTE and doubling of the risk for ATE compared to the risk associated with use of the four low-dose estrogen CHCs,"" said Stephen Sidney, MD, MPH, director of Research Clinics at the Kaiser Permanente Northern California Division of Research and lead author of the study. "Though the absolute incidence of venous thromboembolic events is low, the growing number of studies showing an of venous thromboembolic events with drospirenone suggests that drospirenone-containing combined should be used cautiously for women seeking hormonal contraception. We also need more information on the risk of arterial thrombotic events with drospirenone-containing combined hormonal contraceptives because few data have been published."

"To put these numbers into perspective, the risk of developing blood clots is higher when using any than not using them, but still remains lower than the risk of developing blood clots in pregnancy and in the ," said Sidney. "Nonetheless, should consider the risks and benefits of drospirenone-containing pills and a woman's risk for developing a blood clot before prescribing these drugs."

Drospirenone (DRSP) is a of the , progesterone, also referred to as a progestin. During the past 10 years, three new combined hormonal contraceptives (CHC) preparations have been approved for use by the FDA, including drospirenone/ethinyl estradiol pills (DRSP), the norelgestromin /ethinyl estradiol transdermal patch (NGMN), and the etonogestrel/ethinyl estradiol vaginal ring (ETON). Since then, there have been several studies evaluating the risk of thrombotic and thromboembolic events compared to low-dose estrogen CHCs that have been on the market for longer periods of time.

"The results have been mixed, and it is unclear whether the differences in findings arose from differences in study methodologies or differences in the populations studied. As a result, there is a great deal of concern and confusion among women and their providers regarding the safety of these newer preparations relative to older CHCs," Sidney said.

"We performed this retrospective cohort study to address methodological issues using a 'New User' design. We assessed the risk of each of the three newer CHCs relative to low-dose estrogen CHCs in a cohort of new users of CHCs from four geographically and demographically diverse health plans."

The study cohort consisted of 573,680 women, ages 10-55, who were identified as "new users," which was defined as first exposure to any of the three DRSP-containing CHCs or the four low-dose estrogen CHCs during the 2001-2007 study period. The cohort was drawn from two integrated health care programs (Kaiser Permanente Northern California and Kaiser Permanente Southern California) and two state Medicaid programs (Tennessee and Washington).

"While the absolute risks for venous thromboembolic events in patients taking drospirenone-containing birth control pills is low, this research helps inform the conversation health care providers have with patients about their oral contraceptive options," said Tracy Flanagan, MD, director of Women's Health at Kaiser Permanente Northern California. "We offer many oral contraceptive choices and can offer alternatives to drospirenone-containing pills that may be more appropriate for an individual patient. The risks and benefits of any contraceptive should be weighed carefully against the risk of an unintended pregnancy."

The comparator CHCs included levonorgestrel/ethinyl estradiol tablets (LNG10-20), levonorgestrel/ethinyl estradiol tablets (LNG15-30), norethindrone/ethinyl estradiol tablets (NETA), and norgestimate/ethinyl estradiol tablets [NGM].

New users of DRSP had 1.77 times the risk for VTE and 2.01 times the risk of ATE relative to new users of the low-dose estrogen comparators. The increased risk of DRSP was limited to the 10-34 years age group for VTE and 35-55 years group for ATE.

Use of the NGMN patch and ETON vaginal ring were not associated with increased risk of either thromboembolic or thrombotic outcomes. However, the patch and ring are used by far fewer women than DRSP-containing birth control pills.

In a Drug Safety Communication dated April 10, 2012, the FDA wrote that based on its review of observational studies, it has concluded that "drospirenone-containing birth control pills may be associated with a higher risk for blood clots than other -containing pills." The FDA advises that, even though it is unclear whether the increased risk seen for blood clots in some of the epidemiologic studies is actually due to drospirenone-containing birth control pills, women should talk to their health care professional about their risk for before deciding which birth control method to use.

Explore further: Study confirms some contraceptive pills more likely to cause blood clots

Related Stories

Study confirms some contraceptive pills more likely to cause blood clots

October 25, 2011
A study published in the British Medical Journal today confirms previous findings that certain oral contraceptive pills are more likely to cause serious blood clots (venous thromboembolism - VTE ) than others.

Drospirenone-containing contraceptives linked to higher risk of blood clots

November 7, 2011
The use of drospirenone-containing oral birth control pills is linked to a significantly higher risk of blood clots, both deep vein thrombosis and pulmonary embolism, according to an article in the Canadian Medical Association ...

Certain birth control pills may carry higher blood clot risk: FDA

April 10, 2012
(HealthDay) -- U.S. health officials announced Tuesday that birth controls pills containing drospirenone -- a man-made version of the hormone progesterone -- may be associated with a higher risk of blood clots and will require ...

Studies show increased risk of blood clots when taking oral contraception with drospirenone

April 21, 2011
(PhysOrg.com) -- Two new drug safety studies conducted by researchers at Boston University School of Medicine (BUSM) provide strong evidence that women taking oral contraception with drospirenone have an increased risk of ...

Some birth control shows higher clot risk: US

October 28, 2011
Some birth control products, including contraceptive pills, rings and patches for women, carry a significantly higher risk of blood clot than low-dose medications, US regulators said Thursday.

Recommended for you

Study suggests ending opioid epidemic will take years

July 20, 2017
The question of how to stem the nation's opioid epidemic now has a major detailed response. A new study chaired by University of Virginia School of Law Professor Richard Bonnie provides extensive recommendations for curbing ...

Team-based model reduces prescription opioid use among patients with chronic pain by 40 percent

July 17, 2017
A new, team-based, primary care model is decreasing prescription opioid use among patients with chronic pain by 40 percent, according to a new study out of Boston Medical Center's Grayken Center for Addiction Medicine, which ...

Private clinics' peddling of unproven stem cell treatments is unsafe and unethical

July 7, 2017
Stem cell science is an area of medical research that continues to offer great promise. But as this week's paper in Science Translational Medicine highlights, a growing number of clinics around the globe, including in Australia, ...

Popular heartburn drugs linked to higher death risk

July 4, 2017
Popular heartburn drugs called proton pump inhibitors (PPIs) have been linked to a variety of health problems, including serious kidney damage, bone fractures and dementia. Now, a new study from Washington University School ...

Most reproductive-age women using opioids also use another substance

June 30, 2017
The majority of reproductive-age and pregnant women who use opioids for non-medical purposes also use at least one other substance, ranging from nicotine or alcohol to cocaine, according to a University of Pittsburgh Graduate ...

At-risk chronic pain patients taper opioids successfully with psychological tools

June 28, 2017
Psychological support and new coping skills are helping patients at high risk of developing chronic pain and long-term, high-dose opioid use taper their opioids and rebuild their lives with activities that are meaningful ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.