Ace%252525252525252525252525252520inhibitors

# ACE Inhibitors ## Overview Angiotensin-Converting Enzyme (ACE) inhibitors block the conversion of angiotensin I to angiotensin II, leading to decreased systemic vascular resistance and reduced aldosterone secretion. They are first-line agents for hypertension, heart failure, and diabetic nephropathy. ## Primary Indications * Hypertension * Heart failure with reduced ejection fraction (HFrEF) * Post-myocardial infarction * Chronic kidney disease (CKD) with proteinuria ## Adult Dosing *Examples provided for common agents:* * **Lisinopril:** Hypertension start 10 mg daily; maintenance 20–40 mg daily (Max 80 mg/day). * **Enalapril:** Hypertension start 5 mg daily; maintenance 10–40 mg daily (Max 40 mg/day). * **Ramipril:** Hypertension start 2.5 mg daily; maintenance 2.5–20 mg daily (Max 20 mg/day). ## Pediatric Dosing *Dosing is highly weight-based and indication-dependent; always verify with local pediatric protocols/formulary.* * **Lisinopril:** For pediatric hypertension (≥6 years): Initial 0.07 mg/kg/day (up to 5 mg); titrate up to 0.6 mg/kg/day (Max 40 mg/day). * **Enalapril:** For pediatric hypertension (≥1 month): Initial 0.08 mg/kg once daily (up to 5 mg); titrate based on blood pressure response (Max 0.58 mg/kg/day or 40 mg/day). ## Dose Adjustments * **Renal Impairment:** Reduce starting dose and titrate slowly. Generally require dose reduction if CrCl <30 mL/min. * **Hepatic Impairment:** Generally unnecessary, though some agents (e.g., prodrugs like Enalapril) may require caution due to conversion efficiency. * **Volume Depletion:** Reduce starting dose or temporarily discontinue diuretics 2–3 days prior to initiation to prevent first-dose hypotension. ## Contraindications * History of angioedema (hereditary or ACE-inhibitor induced). * Concomitant use with aliskiren in patients with diabetes. * Concomitant use with or within 36 hours of a neprilysin inhibitor (e.g., sacubitril). * Pregnancy (Category D: causes fetal morbidity/mortality if used in 2nd/3rd trimesters). * Bilateral renal artery stenosis. ## Adverse Effects * **Common:** Dry, persistent cough (due to bradykinin accumulation), hyperkalemia, headache, dizziness. * **Serious:** Angioedema (life-threatening airway obstruction), acute renal failure, agranulocytosis (rare), hypotension. ## Key Drug Interactions * **Potassium-sparing diuretics/Potassium supplements:** High risk of hyperkalemia. * **NSAIDs:** May reduce antihypertensive effect and increase risk of acute kidney injury. * **Lithium:** May increase lithium levels/toxicity. * **ARBs/Direct Renin Inhibitors:** Increased risk of hyperkalemia, hypotension, and renal impairment (dual RAAS blockade is generally avoided). ## Monitoring * **Baseline/Titration:** Serum creatinine, BUN, and serum potassium (within 1–2 weeks of initiation or dose change). * **Persistent:** Periodic blood pressure monitoring, electrolytes, and renal function. * **Counseling:** Monitor for signs of angioedema (swelling of face, tongue, or lips) and pregnancy status. ## Clinical Pearls * **Cough:** The dry cough does not respond to cough suppressants. If debilitating, switch to an Angiotensin II Receptor Blocker (ARB). * **First-Dose Hypotension:** Most common in patients who are volume-depleted or on high-dose diuretics. Start low and go slow. * **Renal Protection:** ACE inhibitors are renoprotective in diabetic nephropathy due to efferent arteriolar vasodilation, which reduces intraglomerular pressure, even if an initial mild rise in creatinine occurs. *** *Disclaimer: This information is for educational purposes only. Always consult current, institutional-specific guidelines and the official product monographs (package inserts) before prescribing or administering medication.*