Ace%25252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520inhibitors

# ACE Inhibitors ## Overview ACE inhibitors (e.g., lisinopril, enalapril, ramipril) are a class of medications that block the action of angiotensin-converting enzyme, leading to vasodilation and reduced aldosterone secretion. This results in decreased blood pressure and reduced cardiac workload. ## Primary Indications * Hypertension * Heart failure (systolic dysfunction) * Post-myocardial infarction (in select patients) * Diabetic nephropathy (proteinuric kidney disease) ## Adult Dosing Dosing varies significantly by specific agent and indication. Titration is typically guided by blood pressure response and tolerability. * **Hypertension:** Initial doses are usually low, titrated upwards every 1-4 weeks. Examples: * Lisinopril: Start 10 mg once daily, titrate up to 40 mg once daily. * Enalapril: Start 5 mg once or twice daily, titrate up to 10-40 mg once or twice daily. * Ramipril: Start 2.5 mg once daily, titrate up to 10 mg once daily. * **Heart Failure:** Typically initiated after stabilization of acute symptoms, often in combination with other heart failure medications. Examples: * Lisinopril: Start 5 mg once daily, titrate up to 40 mg once daily. * Enalapril: Start 2.5 mg twice daily, titrate up to 10-20 mg twice daily. * Ramipril: Start 2.5 mg twice daily, titrate up to 5-10 mg twice daily. * **Post-MI:** Typically initiated within 24 hours of MI in hemodynamically stable patients. Examples: * Captopril: Start 6.25 mg three times daily, titrate up to 12.5 mg three times daily. * Enalapril: Start 2.5 mg twice daily, titrate up to 5-10 mg twice daily. * **Diabetic Nephropathy:** Dosing is similar to hypertension indications, aiming for BP control. Specific target doses and titration schedules are often dictated by local protocols and patient response. ## Pediatric Dosing Dosing is less standardized and should be based on weight and clinical response. * **Hypertension:** * Enalapril: 0.07 mg/kg/day to 0.5 mg/kg/day divided once or twice daily. Maximum 40 mg/day. * Lisinopril: 0.08 mg/kg/day to 0.31 mg/kg/day once daily. Maximum 20 mg/day initially, can titrate higher. * Captopril: 0.3 mg/kg/dose to 0.5 mg/kg/dose every 8-12 hours. Maximum 6 mg/kg/day. Consult specific pediatric guidelines for precise dosing. ## Dose Adjustments * **Renal Impairment:** Dose reduction is typically required. Consult specific drug monographs for guideline-based adjustments based on creatinine clearance. * **Hepatic Impairment:** Generally minimal dose adjustment needed for prodrugs like enalapril or ramipril. Captopril and lisinopril are not prodrugs and may require less adjustment. ## Contraindications * History of angioedema related to ACE inhibitor therapy * Concomitant use with aliskiren in patients with diabetes mellitus or moderate to severe renal impairment * Pregnancy (especially in the second and third trimesters) * Hypersensitivity to ACE inhibitors ## Adverse Effects * **Common:** Cough (dry, persistent), dizziness, hyperkalemia, fatigue, headache, hypotension. * **Serious:** Angioedema (rare but life-threatening), acute kidney injury, hyperkalemia, elevated liver enzymes. ## Key Drug Interactions * **Potassium-sparing diuretics (e.g., spironolactone, amiloride), potassium supplements, trimethoprim:** Increased risk of hyperkalemia. * **NSAIDs:** May reduce antihypertensive effect and increase risk of renal impairment. * **Diuretics:** Additive hypotensive effect. * **Lithium:** Increased serum lithium levels and risk of toxicity. * **ARBs and Sacubitril/Valsartan:** Increased risk of angioedema and hyperkalemia; generally contraindicated or require a washout period. ## Monitoring * **Baseline:** Serum creatinine, electrolytes (especially potassium), blood pressure. * **During therapy:** Blood pressure, serum creatinine, potassium levels (especially with concomitant diuretics, ARBs, or renal impairment). Monitor for cough and angioedema. ## Clinical Pearls * The characteristic dry cough is thought to be due to bradykinin accumulation. * Angioedema can occur at any time during therapy and is a medical emergency. * Initiate at low doses and titrate slowly, especially in the elderly, volume-depleted patients, or those with heart failure. * Monitor renal function closely, as ACE inhibitors can cause acute kidney injury, particularly in patients with bilateral renal artery stenosis. * Discontinue if angioedema occurs. *** **Disclaimer:** This information is intended for healthcare professionals. Always verify current prescribing information and consult authoritative sources for the most up-to-date recommendations before making clinical decisions.