Ace%252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520inhibitors

# ACE Inhibitors ## Overview Angiotensin-Converting Enzyme (ACE) inhibitors are a class of medications primarily used for cardiovascular conditions. They work by blocking the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, leading to vasodilation, reduced aldosterone secretion, and decreased sympathetic nervous system activity. ## Primary Indications * Hypertension * Heart Failure (systolic dysfunction) * Post-Myocardial Infarction (MI) (in select patients) * Diabetic Nephropathy (proteinuria reduction) * Chronic Kidney Disease (CKD) with proteinuria ## Adult Dosing Specific dosing varies significantly by agent and indication. Doses are generally started low and titrated upwards based on clinical response and tolerability. * **Hypertension:** Typical starting doses vary by agent. For example: * Lisinopril: 10 mg orally once daily. Maximum: 40 mg/day. * Enalapril: 5 mg orally once or twice daily. Maximum: 40 mg/day. * Ramipril: 2.5 mg orally once daily. Maximum: 10 mg/day. * **Heart Failure:** Dosing is typically higher than for hypertension. For example: * Lisinopril: 2.5-5 mg orally once daily, titrated up to target doses (e.g., 32.5-40 mg/day). * Enalapril: 2.5-5 mg orally twice daily, titrated up to target doses (e.g., 10 mg twice daily). * **Post-MI:** Typically started within 24 hours of MI if no contraindications exist. Example: * Captopril: 6.25 mg orally three times daily, titrated up to 50 mg three times daily. * **Diabetic Nephropathy/CKD:** Dosing adjusted to achieve proteinuria reduction, often targeting maximum approved doses where tolerated. ## Pediatric Dosing * **Hypertension:** Dosing is weight-based and varies by agent. Doses should be initiated at the lower end and titrated cautiously. * Enalapril: 0.07 mg/kg/day orally once daily (range: 0.05-0.2 mg/kg/day, max 50 mg/day). * Lisinopril: 0.07 mg/kg/day orally once daily (range: 0.07-0.2 mg/kg/day, max 40 mg/day). * Captopril: 0.3 mg/kg/dose orally three times daily (range: 0.3-0.5 mg/kg/dose, max 150 mg/day). * Established pediatric dosing for heart failure and other indications is less common and often relies on expert consultation or off-label use. ## Dose Adjustments * **Renal Impairment:** Dose reduction is often necessary, especially in moderate to severe renal insufficiency. Initial doses may be lower, and titration should be more cautious. Specific guidelines vary by agent and CrCl. * **Hepatic Impairment:** Generally, no dose adjustment is needed for mild to moderate hepatic impairment, but caution is advised. Enalapril may require dose adjustment due to prodrug conversion. ## Contraindications * History of angioedema related to ACE inhibitor therapy. * Concomitant use with aliskiren in patients with diabetes mellitus or renal impairment. * Pregnancy (especially during the second and third trimesters). * Hypersensitivity to ACE inhibitors. ## Adverse Effects * **Common:** Dry cough, dizziness, hyperkalemia, fatigue, headache, rash. * **Serious:** Angioedema (potentially life-threatening), acute kidney injury (especially in susceptible individuals), hypotension, hyperkalemia, elevated liver enzymes, neutropenia/agranulocytosis (rare). ## Key Drug Interactions * **Potassium-Sparing Diuretics, Potassium Supplements, Aldosterone Antagonists, ARBs:** Increased risk of hyperkalemia. Monitor potassium levels closely. * **NSAIDs:** May reduce antihypertensive efficacy and increase risk of renal impairment, particularly in the elderly or volume-depleted patients. * **Diuretics (Thiazide/Loop):** Increased risk of symptomatic hypotension, especially upon initiation. Consider dose reduction of diuretic or initiating ACE inhibitor at a lower dose. * **Lithium:** ACE inhibitors can decrease lithium clearance, increasing lithium toxicity risk. Monitor lithium levels. * **mTOR Inhibitors (e.g., sirolimus, everolimus):** Increased risk of angioedema. ## Monitoring * **Blood Pressure:** Regularly monitor for efficacy and hypotension. * **Renal Function (SCr, BUN):** Monitor at baseline, shortly after initiation/dose increase, and periodically thereafter. * **Serum Potassium:** Monitor at baseline, shortly after initiation/dose increase, and periodically. * **Angioedema:** Educate patients on signs/symptoms and to discontinue medication immediately if they occur. * **Hemoglobin/Hematocrit:** Baseline and periodically, especially in patients with renal disease. * **White Blood Cell Count:** In patients with collagen vascular disease or renal impairment, consider baseline and periodic monitoring. ## Clinical Pearls * Dry cough is a common side effect and may necessitate a switch to an Angiotensin II Receptor Blocker (ARB). * Angioedema is a medical emergency; discontinue ACE inhibitors immediately and manage airway. * Initiate at low doses and titrate slowly, especially in patients who are elderly, volume-depleted, or have renal impairment. * Monitor for signs of hyperkalemia and renal dysfunction. * Avoid in pregnancy due to teratogenicity. *** *Disclaimer: This information is intended for healthcare professionals and should not be a substitute for clinical judgment. Always consult the most current prescribing information and relevant guidelines before initiating or modifying drug therapy.*