In the study, published today in the CMAJ (Canadian Medical Association Journal), Etminan and colleagues from McGill University and the University of Florida analyzed a database of health records for 2.7 million U.S. women using oral contraceptives over 18 months. He sought to determine whether there was a higher rate of gall bladder surgery or hospital admission for gall bladder disease among women using the relatively new drospirenone, compared to levonorgestrel, the oldest and historically most-prescribed oral contraceptive.
All oral contraceptive drugs carry a small increased risk of gall bladder disease; recent lawsuits allege dropsirenone’s risk is greater than the others. Other allegations leveled against the drug by patients and lawyers include harmful effects on the heart and an increased risk of blood clots. This was the first published study to compare the gall bladder risks of the various birth control pills.
While the analysis found a small, statistically significant increased risk of gall bladder disease among users of dropsirenone – as well as two other traditional oral contraceptives – it is not great enough to be deemed clinically relevant or a cause for concern compared to levonorgestrel, says Etminan, a drug safety expert.
“There have been concerns about various risks of dropsirenone raised by consumers and their lawyers that have been covered by the news media, and which may in turn affect the decisions of physicians and their patients,” says Etminan, a pharmacoepidemiologist at the Centre for Clinical Epidemiology & Evaluation at Vancouver Coastal Health Research Institute and an assistant professor in the Dept. of Medicine at UBC.
“This study should give women some reassurance that the drug is as safe as other contraceptives at least with regard to gall bladder disease, and women should weigh this against the increased risk of pregnancy that occurs when switching to another contraceptive drug,” says Etminan.
The study was funded by Fonds de la recherché en Sante du Quebec (FRSQ), the Ministere de la Sante et des Services Sociaux and the McGill University Health Centre.
The UBC Faculty of Medicine provides innovative education programs in health and life sciences, teaching over 3,000 students at the undergraduate, graduate and postgraduate levels. In addition, over 700 researchers/faculty members representing all of the Faculty’s 19 departments, two schools and 15 research centres and institutes received research grants. In 2008/09 the Faculty generated more than one-half of the total research funding of the university ($475.3M). For more information visit www.med.ubc.ca.
Vancouver Coastal Health Research Institute is the research body of Vancouver Coastal Health Authority, which includes BC’s largest academic and teaching health sciences centres: Vancouver General Hospital, UBC Hospital, and GF Strong Rehabilitation Centre. The institute, academically affiliated with UBC Faculty of Medicine, is one of Canada’s top funded research centres, with $102 million in total research funding for 2008/2009. VCH Research Institute brings innovation and discovery to patient care, advancing healthier lives in healthy communities across British Columbia, Canada, and beyond. www.vchri.ca.