Losartan potassium is the generic name of the first angiotensin II receptor antagonist drug marketed. It is mainly used to treat high blood pressure, but is also used to delay progression of diabetic nephropathy. As of 2014, losartan potassium can only be obtained by prescription in the United States.
Losartan was first approved by the U.S. Food and Drug Administration in 1995. It is marketed by Merck & Company Incorporated under the trade name Cozaar. The generic version is available, and was released in 2010. As of 2014, six additional angiotensin receptor blockers are approved for clinical use in the United States. These drugs are known for their excellent side-effects profiles, which are similar to placebos in clinical trials.
Losartan is commonly combined with hydrochlorothiazide to increase its effect on blood pressure. Losartan was also found to improve memory in patients with normal blood pressure under standard and memory-impaired conditions.
The FDA issued a black-box warning in January 2014 stating that losartan can cause fetal toxicity, which leads to injury or death of the fetus, and should not be taken by anyone who is pregnant. Common side effects include upper respiratory infections or stuffy nose, dizziness and back pain. Diabetic patients commonly experience diarrhea, chest pain, fatigue, elevated potassium, low blood pressure and low blood sugar. Low blood pressure and allergic reactions are serious side effects.