Yes, Cozaar (losartan) is safe to treat your high blood pressure. It is also a good choice for many people with kidney disease.

IgA nephropathy is a kidney disorder. It happens when a protein (IgA) settles in the kidneys. This may cause the kidneys to leak red blood cells and protein into the urine. IgA nephropathy can lead to impaired kidney function and/or large amounts of protein in the urine. Too much protein leaking into the urine can cause the hands and feet to swell.

Losartan is a drug called an angiotensin receptor blocker. Other drugs like it include:

• candesartan (Atacand)
• eprosartan (Teveten)
• irbesartan (Avapro)
• olmesartan (Benicar)
• telmisartan (Micardis)
• valsartan (Diovan)

These blockers lower blood pressure by changing the action of the hormone angiotensin II on blood vessels. Angiotensin II causes blood vessels to tighten. By blocking this hormone, blood vessels can relax. And this allows for easier blood flow, which lowers blood pressure.

These blockers have additional benefits within the kidneys. The blockers lower the pressure on the filtration units called glomeruli. This can slow the decline in kidney function in people with many kidney diseases, including IgA nephropathy.

In addition to blood and urine tests that reflect kidney function, your doctor will periodically check how much protein you have in your urine. If the amount of protein decreases, this is a good sign that the angiotensin receptor blocker is working.

As with all drugs, there are potential side effects. The most worrisome side effect of these drugs is an elevated blood potassium level. You will need periodic blood tests to check your potassium level.