Can someone explain why ACE inhibitors angiotensin 2 antagonists have renal side effects

[fierce_kitten_meow]

I understand that they work in the kidneys, but how does this cause the damage to the kidneys??

[tinmuning]

As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function have been reported in susceptible individuals treated with losartan (an angiotensin II antagonist); in some patients, these changes in renal function were reversible upon discontinuation of therapy.

In patients whose renal function may depend on the activity of the renin-angiotensin-aldosterone system (like patients with CHF), treatment with angiotensin converting enzyme inhibitors has been associated with decreased urine production and/or progressive azotemia and (rarely) with acute renal failure and/or death.