Which antihypertensive combination should be avoided due to increased risk of renal dysfunction?

Which antihypertensive combination should be avoided due to increased risk of renal dysfunction?

• A. ACE inhibitors with ARBs
• B. ARBs with beta-blockers
• C. ACE inhibitors with calcium channel blockers
• D. ACE inhibitors with thiazide diuretics

Answer: (A)

Combining two drugs that both suppress the renin-angiotensin-aldosterone system can dangerously lower the pressure inside the glomerulus and reduce filtration, leading to renal dysfunction. An ACE inhibitor decreases the formation of angiotensin II, while an ARB blocks angiotensin II from acting on its receptor. In the kidney, angiotensin II helps constrict the efferent arteriole to preserve GFR when perfusion is reduced. When both drugs are used together, this compensatory mechanism is removed, potentially causing a significant drop in glomerular filtration rate and increasing the risk of acute kidney injury, especially in patients with dehydration, chronic kidney disease, or bilateral renal artery stenosis. There’s also a higher risk of hyperkalemia. While other combinations listed are used in practice, dual RAAS blockade is generally avoided due to this renoprotective risk without substantial additional benefit.

Combining two drugs that both suppress the renin-angiotensin-aldosterone system can dangerously lower the pressure inside the glomerulus and reduce filtration, leading to renal dysfunction. An ACE inhibitor decreases the formation of angiotensin II, while an ARB blocks angiotensin II from acting on its receptor. In the kidney, angiotensin II helps constrict the efferent arteriole to preserve GFR when perfusion is reduced. When both drugs are used together, this compensatory mechanism is removed, potentially causing a significant drop in glomerular filtration rate and increasing the risk of acute kidney injury, especially in patients with dehydration, chronic kidney disease, or bilateral renal artery stenosis. There’s also a higher risk of hyperkalemia. While other combinations listed are used in practice, dual RAAS blockade is generally avoided due to this renoprotective risk without substantial additional benefit.