GENERIC NAME: losartan
BRAND NAME: Cozaar
DRUG CLASS AND MECHANISM: Losartan is an oral medication that belongs to a class of drugs called angiotensin receptor blockers (ARBs). Other ARBs include irbesartan (Avapro), valsartan (Diovan), and candesartan (Atacand). Angiotensin formed in the blood by the action of angiotensin converting enzyme (ACE) is a powerful chemical that attaches to angiotensin receptors found in many tissues but primarily on smooth muscle cells of blood vessels. Angiotensin's attachment to the receptors causes the muscle cells to contract and the blood vessels to narrow (vasoconstrict) which leads to an increase in blood pressure (hypertension). Losartan (more specifically, the chemical formed when the liver converts the inactive losartan into its active form) blocks the angiotensin receptor. By blocking the action of angiotensin, losartan relaxes muscle cells and dilates blood vessels thereby reducing blood pressure.
Losartan was approved by the FDA in April 1995.
PRESCRIBED FOR: Losartan is used for:
- Treating hypertension and reducing the risk of stroke in patients with hypertension and left ventricular hypertrophy (over developed heart muscle).
- Treating diabetic nephropathy (kidney disease) in people with hypertension and type 2 diabetes.
Quick GuideHow to Lower Blood Pressure: Exercise Tips (Pictures)
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Need help identifying pills and medications?
Use the pill identifier tool on RxList.