The FDA informs that new data regarding birth control pills containing drospirenone are being evaluated to determine what the risk of blood clots is. Drospirenone is a synthetic progestin – a female sex hormone. Birth control pills usually contain either progestin or estrogen – they prevent ovulation, among other things to avert pregnancy. The molecular formula of drospirenone is C24H30O3.

The following birth control pills contain drospirenone:

  • Beyaz
    (generic name) Drospirenone, ethinyl estradiol and levomefolate calcium
  • Gianvi
    (generic name) Drospirenone and ethinyl estradiol
  • Loryna
    (generic name) Drospirenone and ethinyl estradiol
  • Ocella
    (generic name) Drospirenone and ethinyl estradiol
  • Safyral
    (generic name) Drospirenone, ethinyl estradiol, and levomefolate calcium
  • Syeda
    (generic name) Drospirenone and ethinyl estradiol
  • Yasmin
    (generic name) Drospirenone and ethinyl estradiol
  • Yaz
    (generic name) Drospirenone and ethinyl estradiol
  • Zarah
    (generic name) Drospirenone and ethinyl estradiol

Any birth control pill carries with it a slight blood clot risk. According to several studies, those containing drospirenone increase the risk more than the ones containing progestin levonorgestrel. However, some studies have shown the drospirenone pills do not increase risk more than the progestin ones.

The FDA says that the risk of DVT (deep vein thrombosis) is still very small for women taking birth control pills. If the clot breaks loose it can be carried by the bloodstream and end up in the lung, causing a potentially life-threatening pulmonary embolism.

The FDA cites two studies published this year which demonstrated a higher risk of blood clots in pills containing drospirenone compared to those with levonorgestrel (progestin). (BMJ 2011; 340:d2139, and BMJ 2011; 340:d2151.)

Two post-marketing studies in the USA and the European Union found no greater risk of blood clots from drospirenone pills compared to those containing levonorgestrel or other progestins.

Two studies published in 2009 did reveal a higher risk in pills containing drospirenone. (BMJ 2009; 339:b2890, and BMJ 2009; 339:b2921).

After reviewing the same data that the FDA is looking at now, EMA (European Medicines Agency) has announced that it is updating product information on birth control pills that contain drospirenone and ethinyl estradiol regarding venous thromboembolism risk.

The FDA urges women not to stop taking their birth control pills before consulting with their doctor.

Source: Food and Drug Administration

Written by Christian Nordqvist