Ace%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520inhibitors

# ACE Inhibitors ## Overview Angiotensin-converting enzyme (ACE) inhibitors are a class of medications that block the conversion of angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor and stimulates aldosterone release, leading to sodium and water retention. By inhibiting ACE, these drugs lead to vasodilation and reduced sodium/water retention, lowering blood pressure. ## Primary Indications * Hypertension * Heart failure (systolic dysfunction) * Post-myocardial infarction (MI) (in select patients) * Diabetic nephropathy (in select patients) * Chronic kidney disease (CKD) with proteinuria (in select patients) ## Adult Dosing Dosing varies by specific agent and indication. Typical starting doses are low, with gradual titration based on blood pressure response and tolerability. * **Hypertension:** * Benazepril: Start 10 mg once daily. Max 40 mg once daily. * Captopril: Start 12.5-25 mg twice daily. Max 150 mg three times daily. * Enalapril: Start 5-10 mg once daily. Max 40 mg once daily. * Fosinopril: Start 10 mg once daily. Max 80 mg once daily. * Lisinopril: Start 10 mg once daily. Max 40 mg once daily. * Moexipril: Start 7.5 mg once daily. Max 30 mg once daily. * Perindopril: Start 2.5-5 mg once daily. Max 10 mg once daily. * Quinapril: Start 10 mg once daily. Max 80 mg once daily. * Ramipril: Start 2.5 mg once daily. Max 10 mg once daily. * Trandolapril: Start 1 mg once daily. Max 4 mg once daily. * **Heart Failure (NYHA Class II-IV):** Dosing often starts lower and is titrated more slowly than for hypertension. Specific guidelines should be followed. * Captopril: Start 6.25 mg three times daily. Max 50 mg three times daily. * Enalapril: Start 2.5 mg twice daily. Max 10 mg twice daily. * Lisinopril: Start 5 mg once daily. Max 40 mg once daily. * Ramipril: Start 2.5 mg twice daily. Max 10 mg twice daily. ## Pediatric Dosing Established for some agents, often used in the management of hypertension. Dosing is typically weight-based and may vary by age group. Consult specific pediatric guidelines. * **Captopril:** Hypertension: 0.3-1 mg/kg/dose every 8-12 hours. Max 6 mg/kg/day or 150 mg/day. * **Enalapril:** Hypertension: 0.1-0.5 mg/kg/dose every 8-24 hours. Max 20 mg/day. * **Lisinopril:** Hypertension: 0.07-0.2 mg/kg/dose once daily. Max 40 mg/day. ## Dose Adjustments * **Renal Impairment:** Dose reduction is often necessary, especially for drugs renally eliminated. Monitor serum creatinine and potassium. * Captopril: CrCl <30 mL/min: Reduce dose by 50%. * Enalapril: CrCl <30 mL/min: Start with 5 mg once daily, titrate cautiously. * Lisinopril: CrCl <30 mL/min: Start with 5 mg once daily, titrate cautiously. * **Hepatic Impairment:** Use with caution, may require dose adjustment (e.g., captopril, enalapril). ## Contraindications * History of angioedema related to previous ACE inhibitor treatment. * Hereditary or idiopathic angioedema. * Concomitant use of sacubitril/valsartan (within 36 hours of last dose of sacubitril/valsartan). * Pregnancy (Category D, particularly in the second and third trimesters). * Bilateral renal artery stenosis. * Hypersensitivity to the specific ACE inhibitor. ## Adverse Effects * **Common:** Dry cough, dizziness, fatigue, headache, hyperkalemia, hypotension. * **Less Common/Serious:** Angioedema (can be life-threatening, affecting face, lips, tongue, larynx, intestines), renal insufficiency (especially in those with bilateral renal artery stenosis or severe heart failure), neutropenia/agranulocytosis (rare), hepatotoxicity (rare). ## Key Drug Interactions * **Potassium-sparing diuretics, potassium supplements, salt substitutes:** Increased risk of hyperkalemia. * **NSAIDs, COX-2 inhibitors:** May blunt antihypertensive effect and increase risk of renal impairment, especially in volume-depleted patients or those with pre-existing renal disease. * **Diuretics (especially potassium-wasting):** Additive hypotensive effect. Risk of severe symptomatic hypotension, particularly after first dose of ACE inhibitor. * **Lithium:** Increased lithium levels and risk of lithium toxicity. * **mTOR inhibitors (e.g., sirolimus, everolimus), DPP-4 inhibitors (e.g., alogliptin, saxagliptin):** Increased risk of angioedema. * **Sacubitril/valsartan:** Increased risk of angioedema. Do not use within 36 hours of each other. ## Monitoring * **Blood Pressure:** Regularly to assess efficacy and guide titration. * **Renal Function (Serum Creatinine, BUN):** Baseline and periodically, especially in patients with renal impairment, heart failure, or receiving diuretics. * **Serum Potassium:** Baseline and periodically, especially in patients with renal impairment, those on potassium supplements, or potassium-sparing diuretics. * **Signs/Symptoms of Angioedema:** Patient education is crucial. ## Clinical Pearls * The characteristic dry cough is thought to be due to increased bradykinin levels. It is generally reversible upon discontinuation. * Angioedema is a medical emergency; discontinue immediately if suspected and manage airway. * Initiate at low doses and titrate slowly, particularly in elderly patients, those with heart failure, or renal impairment. * First-dose hypotension can occur, especially in patients who are volume-depleted or on diuretics. Consider withholding diuretics for 2-3 days prior to initiating ACE inhibitor therapy or starting with a lower dose. * ACE inhibitors are generally considered renoprotective in patients with diabetes and proteinuria. *** **Disclaimer:** This information is intended for educational purposes and does not substitute for professional medical advice. Always consult the most current prescribing information, drug monographs, and institutional protocols for definitive dosing, indications, contraindications, warnings, and adverse effects before prescribing or dispensing any medication.