Post Date August, 26 2023
FDA started this meeting. A retrospective study showed that the new oral contraceptive containing drospirenone may have a higher risk of thrombosis than other contraceptives. However, the other two independent large-scale prospective studies (EURAS study in Europe and Ingenix study in the United States) believed that the thrombotic probability of oral contraceptives containing drospirenone was not significantly different from other contraceptives. The FDA hopes to clarify the risks and benefits of the drug through comprehensive discussions among various experts, providing guidance for subsequent medical applications. The conclusion of this meeting indicates that the FDA fully recognizes the benefits of this drug in contraception, but also reminds doctors and patients to pay attention to the risk of blood clots caused by oral contraceptives. For decades, the relationship between oral contraceptives and the risk of blood clots has been extensively studied, and this risk is a rare event with minimal absolute risk.
Thrombosis caused by oral contraceptives is a rare event
All compound oral contraceptives have the problem of increasing the risk of thrombosis, but due to the multiple and complex high-risk factors for thrombosis in women, the risk of thrombosis is not high compared to oral contraceptives. In the explanatory document of this meeting, the FDA stated that due to the normal physiological process of pregnancy and postpartum, the probability of blood clots is 20-30/10000 people, and the probability of blood clots caused by taking oral contraceptives is 9-10/10000 women. The probability of blood clots caused by pregnancy is less than half, making it a rare medical event. Another study shows that the incidence of venous thrombosis in Chinese is far lower than that in white people due to genetic differences.
Compared to oral contraceptives, pregnancy has a higher risk of blood clots, but it does not lead to fertility due to fear of blood clots. Therefore, we should face the risk of thrombosis with oral contraceptives and not be too afraid. According to such data, Bloomberg's report on this incident also mentioned that many doctors say they need to continue prescribing such drugs.
In addition, in the expert committee evaluation supporting data released by FDA on December 6, the European Outlook EURAS research design fully considered the important high risk factors (obesity, smoking, thrombotic family history and other factors) caused by thrombosis, and corrected them, which is scientific.
Identifying and avoiding high-risk factors is key
While focusing on the relationship between oral contraceptives and the risk of thrombosis, the committee's discussion confirmed the key benefit of their contraceptive effectiveness. The FDA's evaluation support materials compared various contraceptive methods, and the contraceptive reliability of the compound oral contraceptive pill is second only to sterilization and higher than the currently most commonly used condoms.
