Health Canada says it is reviewing all available safety information on the drug Diane-35 following France's decision to ban the medication in response to the deaths of four women over the last 25 years.
The women died of blood clots linked to their use of Diane-35, an acne drug that is also widely prescribed as an oral contraceptive because it halts ovulation. It has been sold in France since 1987.
France's National Agency for the Safety of Drugs and Health Products said this week that Diane-35, made by Bayer and licensed in 135 countries, would be withdrawn from sale in three months. Meanwhile, doctors are banned from prescribing the medication.
Available since 1998 in Canada, Diane-35 is approved only for the temporary treatment of severe acne in women who are unresponsive to other treatments, Health Canada said Thursday.
However, the drug is often prescribed "off-label" as a contraceptive.
Blood clots are a rare but well-known side-effect of oral birth control pills and other hormonal products such as Diane-35, said the federal department, noting that the product monograph for the drug contains clear warnings about this potential adverse effect.
Health Canada said Diane-35 should not be used in patients with a medical history that puts them at risk for blood clots, including smoking, being overweight or a family history of the condition.
The department has issued previous warnings about the increased risk of blood clots associated with Diane-35 compared with estrogen/progestogen contraceptives, and has cautioned against using the acne drug for birth control.
Consumers experiencing symptoms of a possible blood clot — including persistent leg swelling, leg pain or tenderness, chest pain, or sudden shortness of breath or difficulty breathing — should seek immediate medical attention.
Doctors should be told about any medications being taken, including Diane-35, Health Canada said.
In 2003, a CBC News investigation revealed that thousands of Canadian women were taking the drug solely for birth control, unaware of the potential risks.