ACE Inhibitors (ACEIs) 💙💊
Class: Antihypertensive (RAAS Inhibitor)
🧬Mechanism of Action
🔹 Blocks ACE enzyme, preventing conversion of angiotensin I → angiotensin II
🔹 ⬇ Vasoconstriction → Lowers BP
🔹 ⬇ Aldosterone → ⬇ Sodium & water retention
🔹 Dilates efferent arterioles in kidneys → Nephroprotective
💊 Indications
✅ Hypertension (HTN)
✅ Heart Failure (HF) with reduced ejection fraction (HFrEF)
✅ Post-MI (Cardioprotective) ❤️
✅ Diabetic Nephropathy & CKD (Renoprotective)
💉Dosing & Administration
💡 Start low, go slow (especially in renal impairment, elderly)
💊 Once daily (except captopril: TID, enalapril, quinapril, ramipril: DIE–BID)
🚫 Avoid in pregnancy (Teratogenic)
| Drug – (PRIL) | Initial Dose | Max Dose |
|---|---|---|
| Benazepril (Lotensin) | 10 mg OD | 80 mg OD |
| Captopril (Capoten) | 50 mg TID | 450 mg/day |
| Cilazapril (Inhibace) | 2.5 mg OD | 10 mg OD |
| Enalapril (Vasotec) | 5-10 mg BID | 40 mg/day |
| Fosinopril (Monopril) | 10 mg OD | 80 mg OD |
| Lisinopril (Prinivil, Zestril) | 10 mg OD | 40 mg OD |
| Perindopril (Coversyl) | 2-4 mg OD | 16 mg OD |
| Quinapril (Accupril) | 10 mg BID | 80 mg/day |
| Ramipril (Altace) | 2.5 mg OD | 10 mg OD/BID |
| Trandolapril (Mavik) | 1 mg OD | 4 mg OD |
💡 Key Differences
- Most are prodrugs, requiring liver activation except lisinopril and captopril.
- most dosed daily
- Captopril has a short half-life → needs TID dosing.
- Enalapril, Quinapril, and Ramipril can be BID.
- Fosinopril does not require renal dose adjustment.
- Captopril must be taken on an empty stomach for proper absorption.
🚨Adverse Effects
⚠ Hypotension (esp. after 1st dose) → (start low & go slow, if on diuretic start at half dose)
⚠ Dry cough (persistent, due to ⬆ bradykinin) (switch to ARB)
⚠ Hyperkalemia (to monitor K+ levels)
❌ Angioedema → Swelling of face, lips, tongue, throat (life-threatening!) (D/C and switch to class other then ACE and ARBs)
❌ Acute kidney injury (AKI) → Sudden ↑ SCr, ↓ eGFR
❌ Agranulocytosis/neutropenia , monitor for Fever, sore throat, mouth ulcers
⚡ Drug Interactions
💊 ↑ Risk of Hyperkalemia
Potassium-sparing diuretics ,Potassium supplements, Trimethoprim (TMP)
💊 ↑ Risk of Renal Impairment
🔺 NSAIDs (ibuprofen, naproxen) → risk of AKI 🆘
🔺 Diuretics (loop/thiazide) → potential triple whammy (ACEi + NSAID + Diuretic = Acute kidney injury!)
💊 ↑ Risk of Hypotension
🔺 Diuretics (especially loop)
🔺 Other antihypertensives (e.g., ARBs, CCBs, beta-blockers)
💊 ↑ Lithium Toxicity
🔺 ACE inhibitors ↓ lithium clearance → monitor lithium levels!
🩺Monitoring
📊 Baseline & periodic:
✔ Blood Pressure
✔ Serum Creatinine (SCr), eGFR
✔ Potassium (K+)
✔ Signs of angioedema
💬 Patient Counselling
👂 Report persistent dry cough
🛑 Seek emergency help if facial/lip swelling
💦 Stay hydrated (hypotension risk)
🩺 Monitor BP & kidney function regularly
🍌 Avoid high-potassium foods (bananas, salt substitutes)
❌ Avoid NSAIDs (risk of AKI)
Clinical Pearls 💡
✔ 1st line for HTN, HF, and CKD
✔ Renal protection but monitor SCr (acceptable ↑ up to 30%)
✔ Less effective in Black patients (combine with CCB/thiazide)
✔ Use lower dose in renal impairment (except fosinopril)
✨ Monitor BP, electrolytes, & renal function at baseline, 1-2 weeks after starting, and periodically.
PEBC MCQ Tips 📝
✔ 1st line for HTN (unless Black or contraindicated)
✔ 1st line for HFrEF (improves survival)
✔ Monitor K⁺ & renal function regularly
✔ Switch to ARB if intolerable dry cough
✔ Do NOT use in pregnancy, angioedema, or bilateral renal artery stenosis
PEBC OSCE Tips 🎭
👨⚕️ Patient counseling scenario:
✔ Educate on side effects (esp. cough, dizziness, hyperkalemia)
✔ Explain the need for kidney function monitoring
✔ Angioedema = medical emergency!
✔ Dietary counseling (low-sodium, avoid high-K⁺ foods)
✔ Reinforce adherence for long-term CV protection