I would appreciate any advice on losartan potassium (Cozaar) and its related product losartan potassium/ hydrochlorothiade (Hyzaar). I understand it is in a new class of angiotensin II receptor antagonists for hypertension. As I am writing from Canada, I am unsure if this product is in USA or other countries. I could find no mention of it in recent LactNet posts using the find feature of my E-Mail program. My MD hubby thinks that it should theoretically be safe in breastfeeding as it blocks the Type 1 cardiovascular receptors selectively and not the Type 11 which are in fetal tissue and others. Apologies if this has been brought up before. Rosemarie in St. Paul, AB, Canada [[log in to unmask]]