Ace%2525252525252525252525252525252525252525252525252520inhibitors

## Overview ACE inhibitors (Angiotensin-Converting Enzyme inhibitors) are a class of medications primarily used to treat cardiovascular conditions. They work by blocking the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. This leads to vasodilation, reduced aldosterone secretion, and decreased sympathetic nervous system activity, ultimately lowering blood pressure and reducing cardiac workload. ## Primary Indications * Hypertension * Heart failure (systolic dysfunction) * Post-myocardial infarction (to improve survival) * Diabetic nephropathy (to slow progression) * Chronic kidney disease (in select populations) ## Adult Dosing Dosing is highly individualized and depends on the specific ACE inhibitor, indication, and patient factors. Titration is usually recommended. * **Hypertension:** * Benazepril: Initial 5-10 mg once daily, titrate to 20-40 mg once daily. * Captopril: Initial 6.25-12.5 mg twice or thrice daily, titrate to 25-50 mg twice or thrice daily. * Enalapril: Initial 2.5-5 mg once or twice daily, titrate to 10-20 mg once or twice daily. * Lisinopril: Initial 5-10 mg once daily, titrate to 20-40 mg once daily. * Ramipril: Initial 2.5 mg once daily, titrate to 5-10 mg once daily. * Maximum doses vary but are typically around 40 mg daily for most agents. * **Heart Failure:** * Dosing typically starts lower and is titrated more slowly than for hypertension. * Enalapril: Initial 2.5 mg twice daily, titrate to 10-20 mg twice daily. * Lisinopril: Initial 2.5-5 mg once daily, titrate to 10-40 mg once daily. * Ramipril: Initial 1.25-2.5 mg twice daily, titrate to 5-10 mg twice daily. * **Post-Myocardial Infarction:** * Lisinopril: Initial 5 mg, followed by 5 mg 24 hours later, then 10 mg daily. * Ramipril: Initial 1.25 mg once daily, titrate to 2.5 mg, then 5 mg, then 10 mg once daily over weeks. ## Pediatric Dosing Established pediatric dosing varies significantly by agent and indication. Dosing is often weight-based and may require specialist consultation. * **Hypertension:** * Enalapril: 0.07-0.1 mg/kg/dose once daily, maximum 0.61 mg/kg/day or 40 mg/day. * Lisinopril: 0.07-0.2 mg/kg/dose once daily, maximum 40 mg/day. ## Dose Adjustments * **Renal Impairment:** Dose reduction is typically required. Specific guidelines vary by agent and creatinine clearance. * **Hepatic Impairment:** Use with caution; dose adjustment may be necessary for prodrugs like enalapril and ramipril. ## Contraindications * History of angioedema related to prior ACE inhibitor treatment. * Concomitant use with aliskiren in patients with diabetes mellitus. * Pregnancy (especially in the second and third trimesters, where they can cause fetal injury or death). * Known hypersensitivity to ACE inhibitors. * Bilateral renal artery stenosis. ## Adverse Effects * **Common:** Cough (dry, persistent), dizziness, hypotension, hyperkalemia, fatigue. * **Serious:** Angioedema (potentially life-threatening), acute kidney injury (especially in patients with renal artery stenosis), rash, elevated liver enzymes. ## Key Drug Interactions * **Potassium-Sparing Diuretics (e.g., spironolactone, amiloride), Potassium Supplements, Salt Substitutes:** Increased risk of hyperkalemia. * **NSAIDs:** May reduce antihypertensive effect and increase risk of renal impairment, especially in elderly or volume-depleted patients. * **Aliskiren:** Increased risk of hyperkalemia, hypotension, and renal dysfunction; contraindicated in patients with diabetes. * **ARBs (Angiotensin II Receptor Blockers):** Increased risk of hyperkalemia, hypotension, and renal dysfunction. * **Lithium:** Reduced lithium clearance, leading to lithium toxicity. * **Diuretics:** Additive hypotensive effect; increased risk of volume depletion and hypotension, especially with thiazide diuretics. ## Monitoring * **Blood Pressure:** Regularly, especially after dose initiation or titration. * **Renal Function (Serum Creatinine, BUN):** Baseline and periodically. * **Serum Potassium:** Baseline and periodically, especially in patients with risk factors for hyperkalemia (renal impairment, potassium-sparing diuretics, etc.). * **Angioedema:** Patients should be educated on signs and symptoms. ## Clinical Pearls * The characteristic dry cough is thought to be due to bradykinin accumulation. If cough is bothersome, consider switching to an ARB. * Hypotension can occur, especially after the first dose or in volume-depleted patients. Advise patients to rise slowly. * Angioedema is a medical emergency and requires immediate discontinuation of the ACE inhibitor and appropriate management. * ACE inhibitors are generally considered renoprotective in patients with diabetes and proteinuria. * Avoid use in pregnancy due to potential fetal harm. *** *This information is for educational purposes and is not a substitute for professional medical advice. Always consult with a qualified healthcare provider for any questions you may have regarding a medical condition or treatment. It is essential to verify current prescribing information with the official product monograph or other reliable sources before making any clinical decisions.*