Certain birth control pills and painkillers combined may increase the risk of blood clots in women.

Certain birth control pills and painkillers combined may increase the risk of blood clots in women.

The Surprising Link Between Painkillers and Blood Clot Risk in Women

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It’s no secret that certain forms of birth control carry a small risk of blood clots. However, a recent groundbreaking study suggests that the risk of developing blood clots can be magnified by the use of common painkillers. The study, which examined the medical records of 2 million Danish women, found that the risk of a blood clot was further increased when women used a nonsteroidal anti-inflammatory drug (NSAID) alongside their birth control.

Dr. Amani Meaidi, a researcher with the Danish Cancer Society in Copenhagen and the leader of the study, highlighted this interesting discovery. She stated that the risk associated with simultaneous use of birth control and NSAIDs was larger than the sum of the risks associated with individual use. However, it’s important to note that the absolute risk of developing a blood clot is still very low for women using both drugs.

But what exactly does this mean for women who rely on hormonal birth control and occasionally need NSAIDs for pain relief? Dr. Colleen Denny, the director of family planning at NYU Langone Hospital Brooklyn, firmly believes that women on hormonal birth control shouldn’t worry about using an NSAID temporarily. In fact, an NSAID may be the most effective option for pain relief in certain situations.

It’s crucial to keep the risk of blood clots associated with birth control in perspective. The odds of developing a clot while on birth control are significantly lower than the risk of developing one during pregnancy or in the months immediately following childbirth. Birth control methods such as pills, rings, patches, and intrauterine devices (IUDs) utilize hormones to prevent pregnancy. Some hormonal contraceptives, especially those with higher amounts of estrogen, have long been associated with a small increase in the risk of blood clots. This is because estrogen can raise the levels of certain proteins that contribute to clot formation.

NSAIDs, on the other hand, have also been linked to an increased risk of blood clots. However, little was known about whether using birth control and an NSAID simultaneously amplifies this risk. This study sought to uncover the potential interaction between these two factors.

The researchers analyzed the medical records of 2 million women aged 15 to 49 living in Denmark between 1996 and 2017. During this period, over 8,700 women developed a first-time blood clot either in a leg vein or in the lungs. The study found that NSAID use alone and estrogen-containing birth control alone were both associated with an increased risk of blood clots. However, when used simultaneously, the risk of blood clots showed a notable increase.

To put the numbers into perspective, the estimated risks per week of use were as follows:

  • Around 4 in 100,000 women would develop a blood clot with one week of NSAID use alone.
  • Roughly 2 in 100,000 women would develop a clot with one week of using “high-risk” contraceptives, such as estrogen/progestin patches and rings, and pills with higher estrogen doses (50 micrograms).
  • When women used both high-risk contraceptives and an NSAID, an estimated 23 in 100,000 would develop a blood clot per week of use.

It’s important to note that NSAIDs had a smaller impact on women using “medium-risk” contraceptives, including other birth control pills. The estimated risk of developing a blood clot per week of NSAID use for these women was 11 in 100,000.

Interestingly, the painkillers had no apparent effect on blood clot risk among women using “low-risk” contraceptives such as progestin-only pills and IUDs.

Although blood clots are uncommon complications of certain contraceptives, they can be very serious. Dr. Meaidi emphasized that women who frequently require NSAIDs for pain relief might want to consider a low-risk form of birth control.

In light of this study, when it comes to contraception, doctors already screen for risk factors that can increase the likelihood of blood clots, such as smoking or a history of blood clots. Any woman with concerns about blood clots can explore low-risk contraceptive options, such as an IUD or progestin-only pills.

“The good news,” said Dr. Denny, “is that we have plenty of options.”

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QUESTION: What is pelvic inflammatory disease (PID)? See Answer

For more information on birth control options, Planned Parenthood provides a comprehensive overview.

Sources: – Amani Meaidi, MD, PhD, Danish Cancer Society Research Center, Copenhagen – Colleen Denny, MD, director of family planning, NYU Langone Hospital Brooklyn, associate professor of obstetrics and gynecology, NYU Grossman School of Medicine, New York City – BMJ, Sept. 6, 2023, online