Losartan is used to treat high blood pressure (hypertension). It is also used to lower the risk of stroke in certain people with heart disease. LOSARTAN (loe SAR tan) treats high blood pressure. It may also be used to prevent a stroke in people with heart disease and high blood pressure. It can be used to prevent kidney damage in people with diabetes. It works by relaxing the blood vessels, which helps decrease the amount of work your heart has to do. Losartan, sold under the brand name Cozaar among others, is a medication used to treat high blood pressure (hypertension). [4] It is in the angiotensin receptor blocker (ARB) family of medication, and is considered protective of the kidneys. Losartan oral tablet is a generic drug prescribed to treat high blood pressure, lower stroke risk in adults with high blood pressure and left ventricular hypertrophy, and treat diabetic. Losartan is an angiotensin II receptor blocker (ARB). It works by blocking a substance in the body that causes blood vessels to tighten. As a result, losartan relaxes the blood vessels. A lower blood pressure will increase the supply of the blood and oxygen to the heart. Losartan is used to treat high blood pressure and to help protect the kidneys from damage due to diabetes. It is also used to lower the risk of strokes in patients with high blood pressure and an enlarged heart. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Losartan (Cozaar) is an angiotensin II receptor blocker (ARB) commonly prescribed to treat high blood pressure. Common losartan side effects include dizziness, respiratory infections, and back or joint pain. Fatigue, headache, and digestive issues are also possible. Overview: Losartan is used for high blood pressure or in certain people with high blood pressure or diabetes. Common side effects may include dizziness, stuffy nose, or back pain. Do not drive or. Learn about the side effects of losartan, from common to rare, for consumers and healthcare professionals. Losartan is a prescription drug to treat high blood pressure, diabetic nephropathy, and stroke risk. Learn about side effects, warnings, dosage, and more.