Two FDA Committees will discuss the benefits and potential harms of oral contraceptives that contain drospirenone, after safety concerns have emerged which appear to show a slight elevation of venous thromboembolism risk. According to recent studies, such contraceptives have a higher blood clot risk compared to oral contraceptives containing the progestin, levonorgestrel. The two Committees are the Reproductive Health Drugs Advisory Committee and the Drug Safety and Risk Management Advisory Committee.

Venous thromboembolism refers to a blood clot that forms in a vein, becomes dislodged and is transported elsewhere, such as to the lung or heart. Thrombosis is a medical term for blood clotting, while an embolism is a blood clot that becomes loose and is transported. An embolism that ends up lodged in the lungs is a pulmonary embolism

Drospirenone, molecular formula C24H30O3, is an anti-androgenic synthetic progestin that is commonly used in birth control.

Examples of oral contraceptives that contain drospirenone (primary indication to prevent pregnancy) include:

  • Yasmin, Yaz (Bayer Healthcare) – tablets containing drospirenone/ethinyl estradiol
  • Beyaz, Safyral (Bayer healthcare) – drospirenone/ethinyl estradiol/levomefolate calcium tablets and levomefolate calcium tablets
  • And the generic equivalents of the above-mentioned drugs

New studies that suggest newer types of birth control medications (drospirenone-containing ones) may raise the risk of blood clots, compared to older ones, have made the FDA consider introducing new safety measures. The two Committees meet on Wednesday, December 8th, from 8am to 5pm, at the Marriott Inn and Conference Center, University of Maryland University College (UMUC) 3501 University Blvd. East Adelphi, Maryland.

Although the venous thromboembolism risk is not great, it is still significant, the FDA wrote in a communique – leading to a greater chance of developing a heart attack, blocked blood vessels, lung blockages, and strokes; all potentially fatal conditions.

Oral contraceptive pill, Yaz, was the best-selling drug of its kind in the USA in 2008. The benefits of Yaz and other similar medications are said to be a lower risk of bloating and mood swings, compared to older oral contraceptives. The new ones use a version of a female hormone.

Bayer Healthcare spent a considerable amount of money on TV and magazine advertising promoting Yaz in the US for a three-year period up to 2010 – an unusual move for an oral contraceptive pill, according to TNS Media Intelligence. The ads emphasized the other drugs’ risk of acne, bloating and mood swings.

As safety questions grew regarding drospirenone-containing drugs, regulatory bodies in both North America and Europe became concerned. Bayer had to change its adverts that were allegedly exaggerating Yaz’ benefits. Since then, sales have dropped.

The Agency is also assessing clot risk from recent research on the Johnson & Johnson’s weekly Ortho Evra patch, which uses a different version of progestin. The patch has been on the market for a decade; recent studies suggest there is a greater risk of blood clots in the lungs and legs.

All hormone-based medications raise blood-clotting risk, making it especially difficult to tell them apart risk-wise. There are also several other confounding factors which influence blood-clotting risk, such as genetics (family history), obesity and smoking status.

According to Bayer Healthcare, the difference in blood clot risk between its own medications and older birth control ones is not significant. However, several studies have shown that there is a slight increase in risk for drugs like Yaz, compared to older oral contraceptives – perhaps a 1.5 times higher risk.

Written by Christian Nordqvist