Ace%2525252525252525252525252525252525252520inhibitors

# 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 in heart failure with reduced ejection fraction (HFrEF) and chronic kidney disease (CKD). ## Primary Indications * Hypertension * Heart failure (HFrEF) * Post-myocardial infarction (MI) * Chronic kidney disease (diabetic and non-diabetic proteinuric nephropathy) ## Adult Dosing *Dosing varies significantly by agent (e.g., Lisinopril, Enalapril, Ramipril). Typical initiation is low to avoid first-dose hypotension.* * **Lisinopril (Hypertension):** Start 10 mg daily; Max 40 mg/day. * **Lisinopril (Heart Failure):** Start 2.5–5 mg daily; Target 20–40 mg/day. * **Enalapril (Hypertension):** Start 5 mg daily; Max 40 mg/day. * **Enalapril (Heart Failure):** Start 2.5 mg twice daily; Target 10–20 mg twice daily. * *Note: Always consult local institutional protocols for titration schedules.* ## Pediatric Dosing *Pediatric dosing is highly weight-based and dependent on clinical indication; safety data for patients < 1 month is limited.* * **Hypertension (General):** * **Lisinopril:** 0.07 mg/kg once daily (Max 0.6 mg/kg or 40 mg/day). * **Enalapril:** 0.08 mg/kg once daily (Max 0.6 mg/kg or 40 mg/day). * *Consult current pediatric dosing references (e.g., Harriet Lane Handbook) before prescribing.* ## Dose Adjustments * **Renal Impairment:** Reduce starting doses and monitor creatinine/potassium closely. ACE inhibitors are generally avoided or used with extreme caution in bilateral renal artery stenosis. * **Hepatic Impairment:** Some agents (e.g., enalapril) are prodrugs requiring hepatic activation; monitor closely in severe impairment. ## Contraindications * History of angioedema (hereditary or ACE-inhibitor induced). * Pregnancy (Category D: fetal toxicity and death). * Concurrent use with aliskiren in patients with diabetes. * Use within 36 hours of switching to/from an ARNI (Sacubitril/Valsartan) due to angioedema risk. ## Adverse Effects * **Common:** Dry cough (bradykinin-mediated). * **Serious:** Angioedema (life-threatening, can occur years after initiation), hyperkalemia, acute kidney injury (AKI), hypotension. * **Rare:** Neutropenia, agranulocytosis. ## Key Drug Interactions * **Potassium-sparing diuretics/Potassium supplements:** Increased risk of severe hyperkalemia. * **NSAIDs:** Increased risk of acute renal failure and loss of antihypertensive efficacy. * **Lithium:** May decrease lithium clearance, increasing toxicity risk. ## Monitoring * **Baseline:** Serum creatinine (SCr), blood urea nitrogen (BUN), and serum potassium. * **Follow-up:** Check electrolytes and renal function 1–2 weeks after initiation or dose escalation. * **Parameters:** Monitor blood pressure, presence of "bradykinin cough," and signs of angioedema. ## Clinical Pearls * **The Cough:** If a patient develops a persistent, dry cough, discontinue the ACE inhibitor and consider an Angiotensin II Receptor Blocker (ARB). * **Renal Function:** A transient rise in SCr (up to 30%) is considered acceptable upon initiation, reflecting hemodynamic changes. Persistent rises >30% warrant dose reduction or discontinuation. * **First-Dose Hypotension:** More common in patients who are volume-depleted or on high-dose diuretics. *** **Educational Disclaimer:** This information is for educational purposes only. Clinical practice guidelines change frequently. Always verify current, drug-specific prescribing information via institutional protocols, FDA-approved labels, or reliable clinical software (e.g., Lexicomp, UpToDate) before prescribing or administering any medication.