Increased VTE Risk Associated With NSAID Use in Women Using High-Risk Hormonal Contraception

New research has found that nonsteroidal anti-inflammatory drug (NSAID) use was positively associated with the development of venous thromboembolism (VTE) in women of reproductive age.

The research, conducted in Denmark and published in The BMJ, utilized national registries to identify and track all women aged 15 to 49 years old between 1996 and 2017 who had no prior medical history of venous or arterial thrombotic events, cancer, thrombophilia, hysterectomy, bilateral oophorectomy, sterilization, or infertility treatment.

The resultant dataset included more than 2 million women, and the researchers followed them for a total of 21 million person-years. The primary aim of the study was to investigate the influence of concomitant use of hormonal contraception and NSAIDs on the risk of VTE.

Among the 2 million women studied, 8710 venous thromboembolic events were observed during the follow-up period. When compared with non-use of NSAIDs, the use of these drugs was associated with an adjusted incidence rate ratio (IRR) of VTE. The IRR of VTE was found to be 7.2 (95% CI, 6.0-8.5) in women not using hormonal contraception. However, the risk increased significantly for women using hormonal contraception, particularly high-risk hormonal contraception, where the IRR was 11.0 (95% CI, 9.6-12.6). Women using medium-risk hormonal contraception had an IRR of 7.9 (95% CI, 5.9-10.6), while those on low-/no-risk hormonal contraception had an IRR of 4.5 (95% CI, 2.6-8.1).

Moreover, the study highlighted the number of extra VTE events per 100,000 women over the first week of NSAID treatment compared with non-use. This number was found to be considerably higher for women using high-risk hormonal contraception (23 events per 100,000 women) compared with those on medium-risk (11 events) or low-/no-risk hormonal contraception (3 events).

Although the IRRs were elevated, the actual occurrence of venous thromboembolic events during the initial week following NSAID acquisition remained minimal, even among individuals using high-risk hormonal contraception. “However,” investigators wrote, “considering the highly prevalent indications for use of hormonal contraception and of NSAIDs, studying this association further would be of public interest, especially in regular users of NSAIDs, who might benefit from a low-/no-risk hormonal contraceptive rather than a high-/medium-risk hormonal contraceptive.