Ace%252520inhibitors

# ACE Inhibitors ## Overview Angiotensin-Converting Enzyme (ACE) inhibitors block the conversion of angiotensin I to angiotensin II, resulting in systemic vasodilation, decreased aldosterone secretion, and reduced sympathetic nervous system activity. They are foundational agents for cardiovascular and renal protection. ## Primary Indications * Hypertension (HTN) * Heart Failure with reduced ejection fraction (HFrEF) * Post-Myocardial Infarction (MI) * Diabetic Nephropathy / Chronic Kidney Disease (CKD) with proteinuria ## Adult Dosing * **Lisinopril:** HTN: 10 mg daily (initial); 20–40 mg daily (max). HFrEF: 5 mg daily (initial); 20–40 mg daily (target). * **Enalapril:** HTN: 5 mg twice daily (initial); 40 mg daily (max). HFrEF: 2.5 mg twice daily (initial); 10–20 mg twice daily (target). * **Ramipril:** HTN: 2.5 mg daily (initial); 20 mg daily (max). HFrEF post-MI: 2.5 mg twice daily (initial); 5 mg twice daily (target). *Note: Dosing varies by brand and protocol; always consult current institutional guidelines.* ## Pediatric Dosing * **Lisinopril:** Recommended for children ≥6 years. Initial dose: 0.07 mg/kg once daily (max 5 mg). Titrate based on BP response (max 0.6 mg/kg or 40 mg daily). * **Enalapril:** Initial dose: 0.08 mg/kg once daily (max 5 mg). Titrate based on BP response (max 0.58 mg/kg or 40 mg daily). ## Dose Adjustments * **Renal Impairment:** Reduce starting doses if CrCl <30 mL/min for most agents. Monitor serum creatinine and potassium closely. * **Hepatic Impairment:** Use caution with prodrugs (e.g., enalapril, ramipril) as they require hepatic activation. ## Contraindications * History of angioedema (hereditary or ACE-inhibitor induced). * Concomitant use with aliskiren in patients with diabetes. * Use of sacubitril/valsartan (Entresto) within 36 hours. * Pregnancy (Category D: causes fetal morbidity/mortality if used in 2nd/3rd trimester). * Bilateral renal artery stenosis. ## Adverse Effects * **Common:** Dry, persistent cough (due to bradykinin accumulation). * **Serious:** Angioedema (occurs in 0.1–0.7% of patients; can occur years after initiation), hyperkalemia, acute kidney injury (AKI), symptomatic hypotension. ## Key Drug Interactions * **Potassium-sparing diuretics/Supplements:** Increased risk of life-threatening hyperkalemia. * **NSAIDs:** May reduce antihypertensive effect and increase risk of nephrotoxicity by altering renal hemodynamics. * **Lithium:** ACE inhibitors can reduce the renal clearance of lithium, leading to toxicity. ## Monitoring * **Baseline:** Serum creatinine (SCr), blood urea nitrogen (BUN), and potassium (K+). * **Follow-up:** Check electrolytes and renal function 1–2 weeks after initiation or dose titration. * **Ongoing:** Monitor blood pressure, symptoms of hypotension, and report any signs of facial/tongue swelling immediately. ## Clinical Pearls * **The Cough:** If a patient develops a persistent, dry cough, discontinue the ACE inhibitor. An Angiotensin II Receptor Blocker (ARB) is generally the preferred class substitute. * **First-Dose Hypotension:** More common in patients who are volume-depleted or on high-dose diuretics. Consider holding diuretics 2-3 days before starting an ACE inhibitor if possible. * **Renal Function:** A rise in SCr of up to 30% from baseline is acceptable upon initiation; increases exceeding 30% require clinical investigation. *** **Educational Disclaimer:** This information is intended for educational purposes for healthcare professionals. Drug dosages, indications, and safety profiles are subject to change. Always verify current prescribing information via official pharmacy references (e.g., Lexicomp, UpToDate, or the FDA label) and adhere to institutional clinical protocols before prescribing or administering medication.