Venous Embolism Risk Increased With Hormonal Contraceptions, Especially with NSAIDs for Pain Relief Interview with:
Amani Meaidi, Postdoc, MD, Ph.D.
Danish Cancer Society
Danish Cancer Society Research Center
Copenhagen What is the background for this study?

Response: Use of birth control formulations containing estrogen (combined hormonal contraception) is an acknowledged risk factor for venous thromboembolism.

NSAID use has also been shown to increase risk of thrombosis

NSAID use is likely to be the most common co-medication to hormonal contraception use – still, no study has looked at the effect of concomitant use of hormonal contraception and NSAID on venous thromboembolic risk.

Thus, we decided to study the thrombosis safety of using hormonal contraception and NSAIDs simultaneously. What are the main findings?

Response: Studying around 2 million reproductive-aged women, we found that the highly increased risk of venous thromboembolism with NSAIDs was even higher in women using combined hormonal contraception than in women using progestin-only formulations or no hormonal contraception; potentially suggestive of a drug interaction between combined hormonal contraceptives and NSAIDs.

In numbers:

We estimated that around 4 out of 100,000 women would develop venous thromboembolism per one-week NSAID use

We estimated that around 2 out of 100,000 women would develop venous thromboembolism per one-week use of the types of combined hormonal contraception formulations associated the most the venous thrombosis

We estimated that around 23 out of 100,000 women would develop venous thromboembolism per one-week simultaneous use of NSAID AND combined hormonal contraception

This potentially suggests a synergistic drug interaction between these two drug classes. What should readers take away from your report?

Response: In general, to reduce the risk of venous thromboembolism

  • Women should switch from high-risk hormonal contraceptives to medium-risk or low/no-risk formulations.
  • Women in need of pain relief should consider  alternatives to NSAIDs including non-pharmacological therapy
  • Specifically,  Regular users of NSAIDs among women in reproductive aged should choose a low/no-risk hormonal contraceptive as their choice of hormonal contraception. What recommendations do you have for future research as a result of this study?

Response: This is the first study on the influence of concomitant use of hormonal contraception and NSAIDs on risk of venous thromboembolism. Ideally, the study should be replicated in other populations/countries. 

Basic research should aim to investigate the potential mechanism of the interaction between the two drug classes.  

The study was funded by the Danish Heart Foundation. I have nothing to disclose. 


Meaidi A, Mascolo A, Sessa M, Toft-Petersen A P, Skals R, Gerds T A et al. Venous thromboembolism with use of hormonal contraception and non-steroidal anti-inflammatory drugs: nationwide cohort study BMJ 2023; 382 :e074450 doi:10.1136/bmj-2022-074450,user%20status%20for%20hormonal%20contraception.

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Last Updated on September 7, 2023 by