Ace%25252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520inhibitors

# ACE Inhibitors ## Overview ACE inhibitors are a class of drugs that block the enzyme responsible for converting angiotensin I to angiotensin II, a potent vasoconstrictor. This leads to vasodilation, reduced aldosterone secretion, and decreased sodium and water retention, ultimately lowering blood pressure and reducing cardiac workload. ## Primary Indications * Hypertension * Heart failure (reduced ejection fraction) * Post-myocardial infarction (left ventricular dysfunction) * Diabetic nephropathy (proteinuria) ## Adult Dosing * **Benazepril:** Start at 5-10 mg once daily. Target dose typically 20-40 mg once daily. * **Captopril:** Start at 6.25-12.5 mg two to three times daily. Target dose typically 25-50 mg two to three times daily. Maximum 150 mg three times daily. * **Enalapril (oral):** Start at 2.5-5 mg once or twice daily. Target dose typically 10-40 mg once or twice daily. * **Enalapril (IV):** 1.25 mg IV every 6 hours. * **Fosinopril:** Start at 10 mg once daily. Target dose typically 20-40 mg once daily. * **Lisinopril:** Start at 5-10 mg once daily. Target dose typically 20-40 mg once daily. Maximum 80 mg once daily. * **Moexipril:** Start at 7.5 mg once daily. Target dose typically 15-30 mg once daily. * **Perindopril:** Start at 2.5-5 mg once daily. Target dose typically 5-10 mg once daily. * **Ramipril:** Start at 2.5 mg once daily. Target dose typically 5-10 mg once daily. * **Trandolapril:** Start at 1 mg once daily. Target dose typically 2-4 mg once daily. Dosing should be individualized based on patient response and tolerability. Doses for specific indications may vary based on local protocols. ## Pediatric Dosing * **Hypertension:** Dosing varies by agent and age. * **Captopril:** 0.3 mg/kg/dose every 8-12 hours. Maximum 1 mg/kg/dose every 8-12 hours. * **Enalapril:** 0.08 mg/kg/dose (max 2.5 mg) every 12 hours. Titrate up to 0.4 mg/kg/dose (max 40 mg) every 12 hours. * **Lisinopril:** 0.07 mg/kg/dose (max 5 mg) once daily. Titrate up to 0.6 mg/kg/dose (max 40 mg) once daily. * **Heart Failure:** Generally not recommended for routine use in pediatric heart failure, but may be considered in specific cases under specialist guidance. Always refer to specific pediatric guidelines and consult with a pediatric cardiologist. ## Dose Adjustments * **Renal Impairment:** Reduce initial dose and titrate slowly. Dose adjustments are agent-specific and depend on the degree of renal impairment (CrCl). * **Hepatic Impairment:** Use with caution. May require dose reduction, especially for drugs with significant first-pass metabolism. ## Contraindications * History of angioedema related to previous ACE inhibitor treatment. * Hereditary or idiopathic angioedema. * Concomitant use with aliskiren in patients with diabetes mellitus or renal impairment. * Second and third trimesters of pregnancy. ## Adverse Effects * Cough (dry, persistent) * Hypotension (especially first dose) * Hyperkalemia * Angioedema (rare but serious) * Renal dysfunction (can worsen pre-existing renal failure) * Dizziness, fatigue * Rash * Dysgeusia ## Key Drug Interactions * **Potassium-sparing diuretics, potassium supplements, spironolactone, eplerenone, salt substitutes:** Increased risk of hyperkalemia. * **NSAIDs, COX-2 inhibitors:** May attenuate antihypertensive effect and increase risk of renal impairment, especially in volume-depleted patients. * **Diuretics (loop, thiazide):** Additive hypotensive effect. Risk of severe hypotension with first dose, especially in volume-depleted patients. * **Aliskiren:** Increased risk of hyperkalemia, hypotension, and renal dysfunction. Avoid concomitant use in patients with diabetes or renal impairment. * **Lithium:** Increased risk of lithium toxicity. Monitor lithium levels closely. * **mTOR inhibitors (e.g., sirolimus, everolimus):** Increased risk of angioedema. ## Monitoring * Blood pressure (before and after initiation/dose changes) * Serum potassium * Renal function (serum creatinine, BUN, CrCl) * Signs/symptoms of angioedema and cough ## Clinical Pearls * The characteristic dry cough is often dose-limiting and may resolve upon discontinuation. * First-dose hypotension is more likely in patients who are volume-depleted or on diuretics. Consider holding diuretics prior to initiating ACE inhibitor therapy. * Hyperkalemia risk is increased in patients with renal impairment, diabetes, or those taking potassium-sparing agents. * Angioedema can occur at any time during therapy and is a medical emergency. * Captopril has a shorter half-life and requires more frequent dosing. *** *This information is intended for healthcare professionals. Always consult the most current prescribing information and clinical guidelines for complete details.*