Ace%2525252525252525252520inhibitors

# 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 foundational agents for cardiovascular and renal protection. Common examples include lisinopril, enalapril, and ramipril. ## Primary Indications * Hypertension * Heart Failure with reduced ejection fraction (HFrEF) * Post-Myocardial Infarction * Chronic Kidney Disease (specifically in patients with proteinuria/diabetes) * Diabetic Nephropathy ## Adult Dosing (Examples) * **Lisinopril:** Hypertension: Start 10 mg PO daily; target 20–40 mg daily. Max 80 mg/day. * **Enalapril:** Heart Failure: Start 2.5 mg PO twice daily; titrate to target 10–20 mg twice daily. Max 40 mg/day. * **Ramipril:** Hypertension: Start 2.5 mg PO daily. Max 20 mg/day. * *Note: Specific titration schedules vary by condition and clinician protocol.* ## Pediatric Dosing Dosing is strictly weight-based and varies significantly by agent. * **Enalapril (Hypertension):** 0.08 mg/kg PO once daily; titrate to max 0.5 mg/kg/day (divided once or twice). * **Lisinopril (Hypertension, ≥6 years):** 0.07 mg/kg (max 5 mg) once daily; titrate to max 0.61 mg/kg (max 40 mg) daily. * *Caution: Use absolute pediatric caution; consult institutional formulary or weight-based dosing references (e.g., Harriet Lane).* ## Dose Adjustments * **Renal Impairment:** Reduce starting dose and titrate slowly if CrCl <30 mL/min. Monitor serum creatinine and potassium closely. * **Hepatic Impairment:** Use caution with prodrugs (e.g., enalapril, ramipril) that require hepatic conversion to active metabolites. * **Volume Depleted Patients:** Initiate at 50% of the standard starting dose or hold diuretics 2–3 days prior to initiation to prevent profound hypotension. ## Contraindications * History of angioedema (hereditary or ACE-inhibitor induced). * Pregnancy (Category D: causes fetal morbidity/mortality if used in 2nd/3rd trimester). * Concurrent use with aliskiren in patients with diabetes. * Use within 36 hours of sacubitril/valsartan (Entresto) therapy. * Bilateral renal artery stenosis. ## Adverse Effects * **Common:** Dry, persistent cough (bradykinin-mediated). * **Serious:** Angioedema (can occur at any time during therapy), hyperkalemia, acute kidney injury (AKI), hypotension, and fetal toxicity. ## Key Drug Interactions * **Potassium-sparing diuretics/K+ supplements:** Risk of severe hyperkalemia. * **NSAIDs:** Increased risk of renal impairment and reduced antihypertensive efficacy. * **Lithium:** ACE inhibitors can decrease lithium clearance, increasing toxicity risk. * **ARBs/Direct Renin Inhibitors:** Combined blockade increases risk of hyperkalemia, hypotension, and renal failure. ## Monitoring * **Potassium:** Check at baseline and 1–2 weeks after initiation/titration. * **Renal Function:** Serum creatinine and estimated GFR (CrCl) at baseline and 1–2 weeks after initiation. A rise in creatinine up to 30% is generally acceptable; >30% warrants investigation. * **Blood Pressure:** Monitor for orthostasis and symptomatic hypotension. ## Clinical Pearls * **Cough:** If a patient develops a persistent dry cough, the ACE inhibitor must be discontinued; switching to an Angiotensin II Receptor Blocker (ARB) is a common clinical strategy, as ARBs do not affect bradykinin metabolism. * **Angioedema:** If an ACE inhibitor is implicated in angioedema, it is strictly contraindicated for future use. * **First-dose hypotension:** Most common in patients who are volume-depleted or on high-dose diuretics. *** **Disclaimer:** This information is for educational purposes only. Drug dosing, contraindications, and clinical protocols are subject to change. Always verify current prescribing information, institutional guidelines, and patient-specific factors via professional clinical databases (e.g., Lexicomp, UpToDate) before prescribing or administering medication.