Advisory

2001-90
August 15, 2001

Health Canada advising of possible interaction between warfarin and vaginal miconazole

OTTAWA - Health Canada is issuing an advisory concerning a possible interaction between prescription anti-coagulants (blood thinners) such as warfarin and vaginal miconazole products. Miconazole is an anti-fungal drug that has been available by prescription for many years, and more recently, as over-the-counter non-prescription vaginal creams and suppositories. These creams and suppositories are used to treat vaginal yeast infections.

Women who are taking the prescription blood-thinner warfarin should consult their doctor or pharmacist before using any vaginal miconazole product.

This action has been taken because the U.S. Food and Drug Administration (FDA) has received several reports of adverse events suggesting abnormal blood clotting tests for women who used vaginal miconazole while taking warfarin. In addition to abnormal test results, one woman developed bruises, bleeding gums and a nosebleed. There is one case report in the Canadian Adverse Drug Reaction (ADR) database that is suggestive of an interaction between warfarin and vaginal miconazole.

Health Canada is asking manufacturers of vaginal miconazole products to add a new warning to the Product Monograph and to the product label. The warning will state that those who are taking prescription blood thinners, such as warfarin, should consult with a physician or pharmacist before using vaginal miconazole, due to the risk of bleeding or bruising.

The completeness and accuracy of this list of products containing miconazole depends on the manufacturers notifying Health Canada of any changes. Health Canada strongly advises consumers to check the ingredients list on the product label for the presence of miconazole.

Media inquiries:
Paige Raymond Kovach
Health Canada
(613) 957-1803