Hi, Thanks for writing in. Losartan is a AT1 receptor blocker in the kidneys. In pathologic states, AT1 blockade improves the impaired autoregulation induced by chronic abnormal activation of Renal Artery Stenosis. AT1 receptor blockade has experimentally been shown to decrease renal fibrosis. Losartan may also be able to decrease inflammation by decreasing leukocyte proliferation and blocking upregulation of adhesion molecules. Overal benefits are more when taking losartan. It has not caused any problem to you.