Using painkillers alongside hormonal contraception increases risk of blood clot in women: Study

A large Danish study published by The BMJ recently found that women who use non-steroidal anti-inflammatory painkillers alongside hormonal contraception appear to be at a small increased risk of blood clots known as venous thromboembolism (VTE). The risk was greater in women using combined oral contraceptives containing third or fourth-generation progestins, but smaller in women using progestin-only tablets, implants, and coils, alongside the non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen, diclofenac, and naproxen.

The researchers used national medical records to track first-time diagnoses of venous thromboembolism among 2 million women aged 15 to 49 years living in Denmark between 1996 and 2017 with no history of blood clots, cancer, hysterectomy, or fertility treatment. Hormonal contraception was divided into high, medium, and low risk, according to their association with VTE based on previous studies.

High-risk hormonal contraception included combined estrogen and progestin patches, vaginal rings, and pills containing either 50 mcg of estrogen or third or fourth-generation progestins. Medium-risk contraception included all other combined oral contraceptives and the medroxyprogesterone injection, while progestin-only tablets, implants, and hormone intrauterine devices (coils) were classed as low or no risk. Over an average 10-year monitoring period, 8,710 venous thromboembolic events occurred, and 228 (2.6%) women died within 30 days of their diagnosis.

In absolute terms, NSAID use was associated with four extra venous thromboembolic events per week per 100,000 women not using hormonal contraception, 11 extra events in women using medium-risk hormonal contraception, and 23 extra events in women using high risk hormonal contraception. Among individual NSAIDs, the association was strongest for diclofenac compared with ibuprofen and naproxen.

Reference: BMJ 2023;382:e074450