ACE inhibitors
also: ACEi · -pril · ramipril
Overview
First-line for hypertension (<55, non-Black), heart failure (prognostic), diabetic nephropathy and post-MI. The "-pril" drugs.
Mechanism
Inhibit angiotensin-converting enzyme → ↓angiotensin II (↓vasoconstriction, ↓aldosterone → natriuresis) and ↓bradykinin breakdown (vasodilation + the cough). Net: ↓afterload, ↓preload, reduced glomerular efferent arteriolar tone (↓intraglomerular pressure → renoprotection).
Indications
- Hypertension
- Heart failure (HFrEF) — prognostic
- Diabetic / proteinuric CKD (renoprotective)
- Post-MI / LV dysfunction
The agents
OD
Most-used in HF + secondary prevention.
OD, not a prodrug
Renally cleared.
OD
BD
Adverse effects
Bradykinin-mediated; ~10–15%; switch to an ARB.
↓aldosterone.
Especially with bilateral renal artery stenosis or volume depletion.
Bradykinin; can be life-threatening; higher risk in Black patients.
Cautions & contraindications
Fetotoxic — oligohydramnios, renal dysgenesis, skull defects. Stop and switch (e.g. labetalol/nifedipine).
Efferent arteriole dilation collapses GFR → AKI.
Interactions
- K⁺-sparing diuretics / spironolactone / K⁺ supplements → hyperkalaemia
- NSAIDs → "triple whammy" AKI (ACEi + diuretic + NSAID)
- Aliskiren / ARB combination — avoid
Monitoring & kinetics
U&E + eGFR before, 1–2 weeks after starting/uptitration (accept ≤30% creatinine rise / ≤25% eGFR fall),Serum K⁺,BP
Oral; mostly renal elimination — reduce dose in renal impairment.
Source: BNF — ACE inhibitors · NICE NG136 — Hypertension