Ace%25252525252525252525252525252520inhibitors

# ACE Inhibitors ## Overview Angiotensin-Converting Enzyme (ACE) inhibitors block the conversion of angiotensin I to angiotensin II, leading to decreased systemic vascular resistance and aldosterone secretion. They are foundational agents in cardiovascular and renal management. ## Primary Indications * Hypertension * Heart failure (HFrEF) * Post-myocardial infarction * Chronic kidney disease (CKD) with proteinuria/diabetic nephropathy ## Adult Dosing *Examples provided for common agents:* * **Lisinopril:** Hypertension: Start 10 mg PO daily; target 20–40 mg daily. Heart failure: Start 2.5–5 mg PO daily; target 20–40 mg daily. * **Enalapril:** Hypertension: Start 5 mg PO daily; target 10–40 mg daily (divided). Heart failure: Start 2.5 mg PO BID; target 10–20 mg BID. * **Ramipril:** Hypertension: Start 2.5 mg PO daily; target 10 mg daily. ## Pediatric Dosing Dosing is highly weight-based and dependent on local institutional protocols. * **Enalapril:** 0.08 mg/kg PO once daily (max 0.6 mg/kg/day or 40 mg/day). * **Lisinopril:** 0.07 mg/kg PO once daily (max 0.6 mg/kg/day or 40 mg/day). * *Note: Initiation in pediatric patients should be supervised by a specialist.* ## Dose Adjustments * **Renal Impairment:** Reduce starting doses and titrate slowly. Contraindicated in bilateral renal artery stenosis (or unilateral if solitary kidney). * **Hepatic Impairment:** No specific standard adjustment, but use caution with agents requiring hepatic activation (e.g., prodrugs like enalapril) in severe impairment. ## Contraindications * History of angioedema (hereditary, idiopathic, or ACE inhibitor-induced). * Concomitant use with aliskiren in patients with diabetes. * Pregnancy (Category D/X: ACE inhibitors cause fetal renal injury/anuria). * Concomitant use with sacubitril/valsartan (requires 36-hour washout period). ## Adverse Effects * Dry, persistent cough (due to bradykinin accumulation). * Hyperkalemia (monitor potassium intake and sparing diuretics). * Hypotension (especially with first-dose initiation or volume depletion). * Angioedema (rare but life-threatening). * Acute kidney injury (hemodynamic-mediated). ## Key Drug Interactions * **Potassium-sparing diuretics/supplements:** Increases risk of severe hyperkalemia. * **NSAIDs:** May reduce antihypertensive effect and increase risk of acute kidney injury. * **Lithium:** May increase lithium serum concentrations, leading to toxicity. * **ARB/Direct Renin Inhibitors:** Dual blockade increases risk of hypotension, hyperkalemia, and renal failure. ## Monitoring * **Baseline/Follow-up:** Serum creatinine (SCr), blood urea nitrogen (BUN), and electrolytes (potassium) should be checked within 1–2 weeks of initiation or dose escalation. * **Blood Pressure:** Monitor frequency post-initiation. * **Assessment:** Monitor for signs of angioedema. ## Clinical Pearls * **Cough:** If a persistent cough develops, consider an ARB, which does not inhibit the breakdown of bradykinin. * **First-dose effect:** Start at low doses, particularly in volume-depleted or heart failure patients, and consider evening administration to mitigate symptomatic hypotension. * **Renal Protection:** A minor rise in SCr (up to 30%) following initiation is typically expected due to hemodynamic changes; however, it must be monitored to ensure it stabilizes. *** *Disclaimer: This information is for educational purposes only. Clinical practice guidelines change frequently; always verify specific dosing, safety profiles, and institutional protocols via current drug monographs (e.g., Lexicomp, Micromedex) or local pharmacy clinical resources before prescribing or administering medication.*