ACE Inhibitors and ARBs

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Questions and Answers

Which of the following mechanisms is most directly responsible for the increased risk of angioedema associated with ACE inhibitors, but not with ARBs?

Inhibition of aldosterone release, causing electrolyte imbalances.
Accumulation of bradykinin due to reduced breakdown. (correct)
Increased levels of Angiotensin II leading to AT1 receptor activation.
Direct blockade of AT1 receptors preventing vasoconstriction.

A patient with hypertension and a history of ACE inhibitor-induced cough is prescribed an ARB. Which statement best describes the rationale for this therapeutic switch?

ARBs block the conversion of Angiotensin I to Angiotensin II, preventing the accumulation of bradykinin in the lungs.
ARBs prevent Angiotensin II from binding to AT1 receptors without affecting bradykinin metabolism, thus avoiding the cough side effect. (correct)
ARBs act on the same biochemical pathway as ACE inhibitors, but at a different point that does not affect Angiotensin I.
ARBs directly increase bradykinin levels, counteracting the cough side effect.

How do ACE inhibitors and ARBs comparatively affect Angiotensin II (ANG2) levels and what are the subsequent physiological consequences?

ACE inhibitors prevent ANG2 production with no impact on renal blood flow; ARBs only affect ANG2's ability to bind to receptors, having no impact on overall ANG2 levels or renal blood flow.
ACE inhibitors increase ANG2, leading to decreased SVR, while ARBs decrease ANG2, leading to increased SVR.
ACE inhibitors prevent ANG2 production, leading to vasodilation; ARBs increase ANG2 due to AT1 receptor blockade, also leading to vasodilation. (correct)
ACE inhibitors decrease ANG2, leading to decreased renal blood flow, while ARBs increase ANG2, leading to increased renal blood flow.

Considering the mechanisms of action of ACE inhibitors and ARBs, which of the following scenarios would be of greatest concern regarding potential drug interaction?

A patient taking an ACE inhibitor who requires a potassium-sparing diuretic. (C) Signup and view all the answers

A researcher is designing a study to compare the effectiveness of ACE inhibitors and ARBs in patients with diabetic nephropathy. What is the most critical ethical consideration they must address in the study design?

The equipoise principle, ensuring genuine uncertainty about which treatment is superior before randomization. (A) Signup and view all the answers

How does the impact on Angiotensin I levels differ between ACE inhibitors and ARBs, and what is the physiological significance of this difference?

ACE inhibitors do not prevent the formation of Angiotensin I (↓ ANG1); ARBs lead to less Angiotensin I than in ACE inhibitors. (C) Signup and view all the answers

Which of the following parameters would best reflect the distinct impact of ACE inhibitors on renal hemodynamics compared to ARBs in a patient with renal artery stenosis?

A more pronounced decrease in efferent arteriolar tone with ACE inhibitors, potentially reducing GFR, compared to ARBs. (D) Signup and view all the answers

In a patient with heart failure, how do ACE inhibitors and ARBs affect cardiac remodeling differently, considering their distinct mechanisms of action?

ACE inhibitors reduce Angiotensin II production, preventing maladaptive remodeling; ARBs block AT1 receptors, mitigating the effects of Angiotensin II without directly reducing levels; both prevent the same maladaptive processes. (A) Signup and view all the answers

A clinical trial is designed to evaluate the effects of candesartan and lisinopril on cardiovascular outcomes in high-risk patients. Which factor would be most important to consider when selecting the primary endpoint for the study?

The composite outcome of myocardial infarction, stroke, or cardiovascular death, as this reflects the drugs' long-term impact. (D) Signup and view all the answers

A researcher aims to investigate the effects of telmisartan on renal blood flow in hypertensive patients with chronic kidney disease. Which study design would best isolate the specific effects attributable to telmisartan?

A randomized, placebo-controlled crossover trial where patients receive telmisartan or placebo in random order, with washout periods between treatments to evaluate medication effect. (D) Signup and view all the answers

Flashcards

ACE Inhibitors Mechanism

Inhibits the Angiotensin-Converting Enzyme, preventing the production of Angiotensin II, leading to vasodilation and reduced blood pressure.

ARBs Mechanism

Blocks the Angiotensin II receptor (AT1), preventing vasoconstriction and aldosterone release, leading to vasodilation and reduced blood pressure.

ACE Inhibitors Indications

Hypertension and heart failure treatment with vasodilation and blood pressure reduction.

ARBs Indications

Hypertension, congestive heart failure, and diabetic nephropathy treatment by vasodilation and reduced blood pressure.