In patients who cannot tolerate ACE inhibitors, which is used as an alternative RAAS blocker?

• A. ARBs
• B. ACE inhibitors
• C. ARNi
• D. MRAs

Answer: (A)

When ACE inhibitors can’t be used because of intolerance, the best alternative to block the RAAS is an angiotensin II receptor blocker. ARBs prevent angiotensin II from activating the AT1 receptor, yielding similar hemodynamic and remodeling benefits as ACE inhibitors but with a lower risk of cough and angioedema since bradykinin isn’t increased. Mineralocorticoid receptor antagonists act downstream and are usually added to RAAS blockade rather than used as a direct substitute, while ARNi (combining an ARB with a neprilysin inhibitor) provides additional benefits but is not the standard first substitute specifically for ACE inhibitor intolerance.