Women of childbearing age using the hypertension drugs Hyzaar or Cozaar should be counseled about the consequences of using the medication if they become pregnant, and women who become pregnant while taking the drug should discontinue it as soon as possible due to new studies that show the drugs may put developing fetuses at risk for birth defects and death.
Hyzaar (losartan potassium hydrochlorothiazide) and Cozaar (losartan potassium) are drugs that work directly on the renin-angiotensin system, a hormone system in the body that regulates blood pressure and water or fluid balance. They are in a class of drugs known as angiotensin receptor blockers, or ARBs. Other drugs in this class include Avapro (irbesartan), Diovan (valsartan), and Atacand (candesartan). These drugs are mainly used to treat high blood pressure.
The Food and Drug Administration (FDA) has ordered the safety labels of Hyzaar and Cozaar to include a black box warning for fetal toxicity and its classification changed to Pregnancy Category D. Black box warnings are the strongest warning the FDA requires and signifies that medical studies indicate that use of the drug carries a significant risk of serious or life threatening adverse effects.
A Pregnancy Category D classification is reserved for drugs for which there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, or studies in humans; however, potential benefits may warrant use of the drug in pregnant women despite the potential risks.
Women are advised to tell their doctors as soon as possible if they become pregnant while taking Hyzaar or Cozaar.