Ace%2520inhibitors

# ACE Inhibitors ## Overview Angiotensin-Converting Enzyme (ACE) inhibitors block the conversion of angiotensin I to the potent vasoconstrictor angiotensin II, reducing systemic vascular resistance and aldosterone secretion. They are first-line agents for hypertension, heart failure, and diabetic nephropathy. ## Primary Indications * Hypertension * Heart failure (HFrEF) * Post-myocardial infarction * Chronic Kidney Disease (CKD) / Diabetic nephropathy (proteinuria reduction) ## Adult Dosing *Dosing varies by specific agent (e.g., Lisinopril, Enalapril, Ramipril). Refer to local formulary.* * **Lisinopril (Hypertension):** Start 10 mg daily; maintenance 20–40 mg daily. Max 80 mg/day. * **Lisinopril (Heart Failure):** Start 2.5–5 mg daily; titrate to target 20–40 mg daily. * **Enalapril (Hypertension):** Start 5 mg daily; maintenance 10–40 mg daily (divided bid). Max 40 mg/day. * **Ramipril (Hypertension):** Start 2.5 mg daily; maintenance 2.5–20 mg daily. Max 20 mg/day. ## Pediatric Dosing *Safety and efficacy vary significantly by age and indication. Consult current pediatric references (e.g., Harriet Lane).* * **Lisinopril (Hypertension, ≥6 years):** Initial 0.07 mg/kg/day (up to 5 mg). Titrate at 1–2 week intervals. Max 0.61 mg/kg/day (or 40 mg). * **Enalapril (Hypertension, ≥1 month):** Initial 0.08 mg/kg once daily. Titrate based on response. Max 0.58 mg/kg/day. ## Dose Adjustments * **Renal Impairment:** Reduce starting doses and titrate slowly for CrCl <30 mL/min. * **Hepatic Impairment:** Use caution; individualize based on drug metabolic pathway. * **Volume Depletion:** Temporarily discontinue diuretics 2–3 days before initiating ACE inhibitors to avoid severe hypotension. ## Contraindications * History of angioedema (hereditary or ACE-inhibitor induced). * Concurrent use with aliskiren in patients with diabetes. * Concomitant use within 36 hours of sacubitril/valsartan (risk of angioedema). * Pregnancy: Causes fetal renal abnormalities and oligohydramnios (Boxed Warning). ## Adverse Effects * **Common:** Dry, persistent, non-productive cough (due to bradykinin accumulation). * **Serious:** Angioedema (can occur years into therapy), hyperkalemia, acute kidney injury (AKI), symptomatic hypotension. ## Key Drug Interactions * **Potassium-sparing diuretics/Supplements:** Increased risk of severe hyperkalemia. * **NSAIDs:** May reduce antihypertensive effect and increase risk of acute renal failure. * **Lithium:** May increase serum lithium levels, leading to toxicity. ## Monitoring * **Baseline:** Serum creatinine, BUN, potassium, and blood pressure before therapy and after each dose titration. * **Ongoing:** Monitor electrolytes and CrCl within 1–2 weeks of initiation or dose increases. * **Angioedema:** Educate patients to seek emergent care for swelling of the face, lips, tongue, or glottis. ## Clinical Pearls * **Renal Function:** A transient increase in serum creatinine (up to 30%) is considered acceptable upon initiation due to changes in glomerular hemodynamics; beyond that, investigate for renal artery stenosis. * **Cough:** If a patient develops a persistent cough, switch to an Angiotensin II Receptor Blocker (ARB), as they do not affect bradykinin metabolism. * **First-dose effect:** Patients with volume depletion or heart failure are at high risk for orthostatic hypotension; consider initiation at bedtime. *** *Disclaimer: This information is for educational purposes only. Always consult current, reputable clinical resources (e.g., Lexicomp, UpToDate, or institutional guidelines) and official FDA prescribing information before dosing, as clinical protocols may change.*