# ACE Inhibitors and ARBs: Shared Benefits, Different Tolerability

Use one RAAS blocker for a clear indication, check creatinine and potassium after changes, and distinguish an expected hemodynamic effect from a dangerous reaction.

![Infographic: ACE Inhibitors and ARBs: Shared Benefits, Different Tolerability](https://urinenephrology.org/visual-reference/images/student-ace-arb.png?v=20261003c)

## Similar pathway, different tolerability

ACE inhibitors reduce angiotensin II formation and increase bradykinin; ARBs block AT1 signaling without the same bradykinin effect. Both reduce efferent arteriolar tone and can lower intraglomerular pressure. Choose by disease indication and tolerance, not a universal class ranking.

## Albuminuria creates a kidney indication

KDIGO supports ACE inhibitor or ARB for appropriate CKD with A2/A3 albuminuria, particularly diabetes. Use the highest approved tolerated dose when indicated. Do not combine ACE inhibitor plus ARB; dual blockade increases harm without a routine added clinical benefit.

## Check before and after

Measure BP, creatinine, and potassium and review depletion, NSAIDs, diuretics, potassium supplements, and MRA/trimethoprim exposure. Recheck within 2–4 weeks after starting or increasing the dose, earlier when the patient’s clinical risk warrants it.

## Interpret a creatinine rise

A hemodynamic rise can occur. If creatinine increases >30% within 4 weeks, investigate volume depletion, intercurrent AKI, NSAIDs, excessive diuresis, or renovascular disease and review the dose. Do not permanently discontinue solely for a small stable expected change.

## Distinguish cough from angioedema

Troublesome ACE inhibitor cough may permit an ARB alternative. Lip/tongue/throat swelling requires urgent airway assessment and permanent avoidance of the culprit ACE inhibitor. A history of ACE/ARB-related angioedema also contraindicates sacubitril/valsartan; the transition is not a workaround.

## Preserve benefit safely

Address manageable hyperkalemia with cause review and indicated treatment; symptomatic hypotension or uncontrolled potassium may require reduction/holding. Avoid these drugs in pregnancy and arrange a preconception plan. After illness-related interruption, document reassessment and restart responsibility.

## Supporting evidence

- [Supporting guideline or source](https://kdigo.org/wp-content/uploads/2026/04/KDIGO-2024-CKD-Guideline.pdf)
- [Supporting guideline or source](https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?name=ENTRESTO&setid=000dc81d-ab91-450c-8eae-8eb74e72296f)

## Source lessons

- [raas inhibitors student handout](https://urinenephrology.org/student-resources/pharmacology/raas-inhibitors-student-handout.html)

Read alongside the full lessons; the findings and decisions shown here require the stated clinical context.