Health Canada initiated a safety review of Diane-35 in February 2013, following its ban in France after the deaths of four women from blood clots linked to the drug since 1988. Health Canada approved Diane-35 for the Canadian market in 1998 for the short-term treatment of severe acne in women, for whom other treatments have been unsuccessful. Although Diane-35 was approved to be prescribed for only short-term use, it has also been prescribed off-label to women as a birth control pill because it halts ovulation.
Blood clots are a known side-effect of oral birth control pills and other hormone-containing products, including Diane-35. Its product monograph contains clear warnings about this potential side effect. Diane-35 is, however, associated with an increased risk for blood clots, as compared with estrogen/progestogen-containing contraceptives. Health Canada has issued warnings about this increased risk (December 19, 2002, April 10, 2003, May 12, 2005) and has cautioned against prescription of Diane-35 for birth control purposes; however 800,000 women were prescribed Diane-35 in 2002. 315,000 women in France were prescribed Diane-35 (Dianette in France) and its generics (Cyestra-35 and Novo-Cyproterone/Ethinyl Estradiol). According to IMS Brogan data, almost 500,000 prescriptions of Diane-35 were given to women in Canada in 2012. The majority of these women were prescribed Diane-35 off-label as an oral contraceptive and remained on this pill for long-term use, despite the above warnings by Health Canada. Women prescribed Diane-35 for long-term use grew through 2003 and onward, into their teens, and through menopause.
Health Canada conducted an evaluation of Diane-35's safety and concluded that "...the drug's benefits continue to outweigh the risks, when used as authorized" (see Health Canada's conclusion here). Health Canada's decision-making processes that led to this conclusion have been kept secret and have remained undisclosed. This is particularly important because studies have shown that Diane-35 is four-times more likely to cause major clotting in women, as compared with women who are not prescribed contraceptives. Studies also indicate that Diane-35 is twice as likely to cause major clotting in women, as compared with women who are prescribed other contraceptives.
Health Canada has kept over 150 of its own safety evaluations secret and classified in 2013 alone.
Canadian physicians continue to prescribe Diane-35 off-label as a birth control pill, despite Health Canada's warnings.
Dr. Barbara Mintzes of the University of British Columbia and Therapeutics Initiative argues that pharmaceutical safety information should be neither kept secret, nor confidential. Furthermore, Health Canada's safety evaluations must be made publicly available, rather than only via Access to Information requests, which may provide documents with important information that is "blacked out" because it is proprietary to the sponsoring company.
Health Canada's safety reviews of medications and data used in its decision-making processes must be publicly released, easily available to, and accessible by the Canadian population - the consumers of medications approved by Health Canada.
Drug Regulatory Failure in Canada: The Case of Diane-35
Diane-35: Reconsidering the Risks
Health Canada reviewing safety of drug Diane-35
Health Canada to review safety of drug Diane-35Health Canada review of controversial acne drug kept secret
Health Canada to review Diane-35, acne and contraceptive drug linked to women’s deaths from blood clots
Diane-35 benefits outweigh risks when used as directed: Health Canada