Progestogens’ biliary problems
The need for cholecystectomy in women taking oral contraceptive pills containing ethinyl oestradiol and drospirenone has led to litigation in North America. This has prompted research into a possible link between drospirenone and gall bladder disease.
Researchers analysed a database containing health information on 78 million Americans, including 2,721,014 women who had taken a combined contraceptive pill for at least six months.
There were 27,087 cases of cholecystectomy among the women. Factors significantly associated with gall bladder disease included, smoking, obesity and pancreatitis.
After adjusting for these factors the effect of the contraceptive pills could be assessed. The different progestogens were compared with pills containing levonorgestrel.
The risk of cholecystectomy was significantly increased in women taking pills containing desogestrel, drospirenone and norethindrone.
There were 567,447 women who used oral contraception for at least two years. They had a significantly increased risk of cholecystectomy, if they were taking pills containing drospirenone or ethynodiol diacetate.
Oestrogens and progestogens have a role in the formation of gall stones, so GPs have long been aware that the oral contraceptive pill increases the risk of gall bladder disease. This study shows that the newer pills are no better in this regard than older pills.
Although gall bladder disease was more frequent in women taking pills containing drospirenone, the difference was small and may not be clinically important. According to this study, for every 550 women who take drospirenone instead of levonorgestrel, for at least six months, one will need a cholecystectomy.
Dr John Dowden
CMAJ 2011; 183:899-904
Tags: , Research Update