AHRQ Research Informs Warning from Canadian Government About ACE Inhibitor Use During Pregnancy

Comparative Effectiveness
December 2007

As a result of research partly funded by AHRQ, the Canadian government has issued an advisory that pregnant women should not use blood pressure medication known as ACE (angiotensin-converting enzyme) inhibitors. The research was conducted at the AHRQ-sponsored Center for Education and Research on Therapeutics at Vanderbilt University.

Officials at Health Canada issued the warning after seeing a study in the New England Journal of Medicine, which found that ACE inhibitors may be associated with increased risk of birth defects throughout pregnancy. William Cooper, MD, MPH, led the research at Vanderbilt Children's Hospital that resulted in the journal article.

It was previously established that ACE inhibitors were potentially dangerous in the second and third trimesters of pregnancy. However, the journal article revealed an additional risk during the first trimester of pregnancy when such medications are used.

As a result of this new information, manufacturers of all ACE inhibitors approved for sale in Canada were required to update medication labeling to include a warning that the product is not to be used by women who are pregnant or might become pregnant.

Health Canada officials have urged pregnant women, or those who may become pregnant, to discuss with their physicians the use of an alternate blood pressure drug. There are many Health Canada-approved drugs to treat high blood pressure that do not contain ACE inhibitors.

Health Canada is the Federal department responsible for helping Canadians maintain and improve their health. Health Canada plays an active role in ensuring access to safe and effective drugs and health products.

Impact Case Study Identifier: 
AHRQ Product(s): CERTs
Topics(s): Women's Health, Heart Health, Pediatrics
Geographic Location: Canada
Implementer: Health Canada
Date: 12/01/2007

Cooper WO, Hernandez-Diaz S, Patrick G, et al. Major congenital malformations after first-trimester exposure to ACE inhibitors. New England Journal of Medicine 2006; 354(23): 2443-51.

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