Question: why are arbs contraindicated in renal artery stenosis?
Answer: Azotemia sets in when angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) cause efferent arteriolar dilatation, thereby decreasing intraglomerular pressure and filtration. Therefore, ACE inhibitors and ARBs are contraindicated in bilateral renal artery stenosis.