The TGA is aware of two recently published studies that reported a greater risk of blood clots, also known as venous thromboembolism (VTE) in women taking oral contraceptives containing the progestogen drospirenone when compared to oral contraceptives containing the progestogen levonorgestrel.
These studies compared the risk in women taking oral contraceptives containing drospirenone to ones containing a different progestogen, levonorgestrel.[1,2]
Oral contraceptive pills registered for use in Australia that contain drospirenone are Yaz and Yasmin. These oral contraceptives are not available on the Pharmaceutical Benefits Scheme (PBS).
The TGA has reviewed the available information and has assessed the risks of VTE associated with drospirenone-containing oral contraceptives. The TGA has been working with the sponsor to amend the product information to incorporate this new evidence. The published studies suggest a two- to three-fold increase in the risk of VTE in women who take drospirenone-containing oral contraceptives when compared to women taking contraceptives containing the progestogen levonorgestrel; however there were a number of limitations in these studies, including a lack of information on confounding factors.
Conclusion
All oral contraceptives pose a small risk of VTE. This risk is influenced by age, family history of VTE and lifestyle factors such as weight and smoking.
At this stage, the TGA has no plans to remove or restrict the sale of these products from the Australian market. However, the TGA will continue to closely monitor and assess all new information and will take whatever regulatory action is required to protect the safety of consumers. The TGA will also communicate any safety concerns to the public as it becomes available.
About drospirenone
Drospirenone is a type of female sex hormone called a progestogen. Most oral contraceptive pills contain two types of hormones; an oestrogen and a progestogen. Oral contraceptives work by preventing the release of eggs from the ovaries (ovulation) and changing the cervical mucus and the lining of the uterus to prevent pregnancy.
Information for patients
If your oral contraceptive pill contains drospirenone, you are advised not to stop taking it; if you have concerns you should discuss alternative forms of contraception with your doctor.
Contact your doctor immediately or go to the Emergency Department at your nearest hospital if you develop any symptoms of blood clots, such as:
- persistent leg pain;
- severe chest pain; or
- shortness of breath.
Information for health professionals
Health professionals should weigh the clinical needs of their patients against the possible slight increase in the risk of VTE and should educate their patients to recognise the signs and symptoms of VTE.
Health professionals are encouraged to report all adverse events associated with all oral contraceptives via the online reporting form available from the TGA website.
References
- Parkin L, Sharples K, Hernandez RK, Jick SS. Risk of venous thromboembolism in users of oral contraceptives containing drospirenone or levonorgestrel: nested case-control study based on UK General Practice Research Database. BMJ 2011; 340:d2139.
- Jick SS, Hernandez RK. Risk of non-fatal venous thromboembolism in women using oral contraceptives containing drospirenone compared with women using oral contraceptives containing levonorgestrel: case-control study using United States claims data. BMJ 2011; 340:d2151.