Ace%25252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520inhibitors

# ACE Inhibitors ## Overview Angiotensin-Converting Enzyme (ACE) inhibitors are a class of drugs primarily used to treat hypertension and heart failure. They work by blocking the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, leading to vasodilation and decreased blood pressure. ## Primary Indications * Hypertension * Heart Failure (NYHA Class II-IV) * Post-Myocardial Infarction (to improve survival) * Diabetic Nephropathy (proteinuria reduction) * Chronic Kidney Disease (proteinuria reduction) ## Adult Dosing Dosing is highly individualized and depends on the specific ACE inhibitor. Common agents and starting doses include: * **Benazepril:** 10 mg once daily. Max: 40 mg daily. * **Captopril:** 25 mg twice daily. Max: 150 mg twice daily. * **Enalapril:** 5 mg once daily. Max: 40 mg daily. * **Fosinopril:** 10 mg once daily. Max: 80 mg daily. * **Lisinopril:** 10 mg once daily. Max: 40 mg daily. * **Moexipril:** 7.5 mg once daily. Max: 30 mg daily. * **Perindopril:** 4 mg once daily. Max: 16 mg daily. * **Quinapril:** 10 mg twice daily. Max: 80 mg daily. * **Ramipril:** 2.5 mg once daily. Max: 10 mg daily. * **Trandolapril:** 1 mg once daily. Max: 4 mg daily. ## Pediatric Dosing Established pediatric dosing varies by agent and indication. Generally, lower doses are used, and titration is cautious. Examples: * **Captopril:** * Hypertension: 0.3 mg/kg/dose orally every 8-24 hours. Max: 6 mg/kg/day. * Heart Failure: 0.1 mg/kg/dose orally every 8-24 hours. Max: 3 mg/kg/day. * **Enalapril:** * Hypertension: 0.07 mg/kg/dose orally once daily. Max: 0.61 mg/kg/day. * Heart Failure: 0.1 mg/kg/dose orally once daily. Max: 0.61 mg/kg/day. Consult pediatric-specific guidelines or drug monographs for precise dosing and indications. ## Dose Adjustments * **Renal Impairment:** Dose reduction is often necessary, especially in severe renal impairment (CrCl < 30 mL/min). Monitor potassium closely. * **Hepatic Impairment:** Cautious initiation with lower doses may be warranted for prodrugs (e.g., enalapril, lisinopril) as hepatic metabolism is required for activation. ## Contraindications * History of angioedema related to previous ACE inhibitor treatment. * Hereditary or idiopathic angioedema. * Concomitant use with aliskiren in patients with diabetes mellitus or moderate to severe renal impairment. * Pregnancy (especially second and third trimesters). ## Adverse Effects * **Dry Cough:** Common, typically non-productive. * **Angioedema:** Rare but life-threatening swelling of the face, lips, tongue, throat, or intestines. Discontinue immediately. * **Hyperkalemia:** Especially with renal impairment or concomitant potassium-sparing diuretics/potassium supplements. * **Hypotension:** Particularly with the first dose or in volume-depleted patients. * **Renal Dysfunction:** Can worsen pre-existing renal impairment, especially in conditions like bilateral renal artery stenosis. * **Dizziness, Fatigue, Headache.** * **Rash.** ## Key Drug Interactions * **Potassium-Sparing Diuretics (e.g., spironolactone, amiloride) and Potassium Supplements:** Increased risk of hyperkalemia. * **NSAIDs:** May blunt the antihypertensive effect and increase risk of renal dysfunction. * **Diuretics:** Increased risk of hypotension, especially with loop diuretics. * **Lithium:** ACE inhibitors can decrease lithium clearance, leading to lithium toxicity. * **Aliskiren:** Increased risk of hyperkalemia, hypotension, and renal dysfunction. Avoid concomitant use in patients with diabetes or renal impairment. * **ARBs (Angiotensin II Receptor Blockers):** Increased risk of adverse events, including renal dysfunction, hyperkalemia, and hypotension. Generally not recommended together. ## Monitoring * **Blood Pressure:** Before and during treatment. * **Renal Function (BUN, Creatinine):** Baseline and periodically, especially with impaired renal function or other risk factors. * **Serum Potassium:** Baseline and periodically, especially with renal impairment or concomitant medications. * **Signs/Symptoms of Angioedema:** Educate patients on this risk. ## Clinical Pearls * Start with low doses and titrate slowly, especially in elderly patients, those with heart failure, or renal impairment. * First-dose hypotension can occur; monitor closely after initiation and dose increases. * Discontinue immediately if angioedema develops. * ACE inhibitors are generally safe and effective in patients with chronic kidney disease to slow progression, particularly if proteinuria is present. * In patients with heart failure, ACE inhibitors have been shown to improve symptoms and reduce mortality. *** *Disclaimer: This information is for educational purposes only and does not substitute for professional medical advice. Always verify current prescribing information, guidelines, and patient-specific factors before making treatment decisions.*