Recent Studies Find That New Progestin Drospirenone Has 1.7 Times Increased Risk Of Developing Blood Clots Compared To Levonorgestrel
(Posted by Tom Lamb at DrugInjuryWatch.com)
For current information, visit the YAZ, Yasmin, Ocella, Gianvi, Zarah, Beyaz, and Safyral Information page at our Drug Injury Law web site for more recent developments regarding personal injury and wrongful death lawsuits that involve YAZ, Yasmin, Ocella, Gianvi, Zarah, Beyaz, and Safyral.
Let's start with an August 13, 2009 MedPage Today article, "Thrombosis Risk with OCs Depends on Progestogen", from which we get this concise summary of the issue from Nick Dunn, MD, of the University of Southampton:
All of the more recent progestogens, possibly except norgestimate, now seem to be at a disadvantage with regard to venous thromboembolism.
This quote comes from Dr. Dunn's editorial, "Oral contraceptives and venous thromboembolism", which accompanied the following two articles published August 13, 2009 by the medical journal BMJ:
- "The venous thrombotic risk of oral contraceptives, effects of estrogen dose and progestogen type: results of the MEGA case-control study"; and,
The MedPage Today article summarized the first BMJ Research article, above, as follows:
[T]he Dutch researchers conducted a case-control study among premenopausal women under 50 at six clinics in the Netherlands.
They enrolled 1,524 cases and 1,760 controls, with the primary outcome established as a first deep venous thrombosis or pulmonary embolism.
They found that oral contraceptives increased the risk of venous thrombosis five-fold compared with non-use (95% CI 4.2 to 5.8).
Using contraceptives that contained levonorgestrel carried a 3.6-fold increased risk of venous thrombosis (95% CI 2.9 to 4.6). But risk was higher for other types of progestogens:
- 5.6-fold for gestodene (95% CI 3.7 to 8.4)
- 6.3-fold for drospirenone (95% CI 2.9 to 13.7)
- 6.8-fold for cyproterone acetate (95% CI 4.7 to 10.0)
- 7.3-fold for desogestrel (95% CI 5.3 to 10.0)
Compared with levonorgestrel, the risk of thrombosis associated with other progestogens increased as follows:
- gestodene (OR 1.6, 95% CI 1.0 to 2.4)
- drospirenone (OR 1.7, 95% CI 0.7 to 3.9)
- desogestrel (OR 2.0, 95% CI 1.4 to 2.8)
- cyproterone acetate (OR 2.0, 95% CI 1.3 to 3.0)
Risk was also positively associated with estrogen dose. Compared with a 30-mcg dose, thrombotic risk decreased 20% with a 20-mcg dose (OR 0.8, 95% CI 0.5 to 1.2) and increased nearly twofold for a 50-mcg dose (OR 1.9, 95% CI 1.1 to 3.4).
They also found that the risk of venous thrombosis was highest during the first three months of use (OR 12.6, 95% CI 7.1 to 22.4).
The popular birth control pills YAZ and Yasmin both contain the progestin drospirenone (DRSP); they are differentiated by the amount of estrogen each contains -- YAZ has a 20-mcg dose while the older Yasmin has a 30-mcg dose (as does its generic equivalent Ocella).
For her August 14, 2009 article, "Women Should Take Safest Birth-Control Pill, Researchers Say", Bloomberg reporter Andrea Gerlin sought out the reaction of Bayer -- which makes YAZ and Yasmin, "the two biggest-selling contraceptives worldwide, according to IMS Health", she reports. Here's all she was able to elicit from the drug company:
“We have not seen the data and can’t comment on it at this point in time and soon as we have seen it, we can evaluate it,” Bayer spokeswomen Friederike Lorenzen said in an interview yesterday. “Patient safety is of utmost importance for us.”
Likewise, we are concerned about the safety of women who use YAZ, Yasmin, and Ocella.
We will continue to monitor medical journals and other authoritative sources for the latest findings about the safety of these three drospirenone-containing birth control pills.
P.S. Excerpt from the Abstract for "Risk of venous thromboembolism among users of oral contraceptives: a review of two recently published studies" (J Fam Plann Reprod Health Care, January 1, 2010):
CONCLUSION: The best evidence continues to suggest that the increased risk of VTE in OC users is a class effect, dependent on the estrogen dose and duration of use, and independent of the progestogen used.