Ace%252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520inhibitors

# ACE Inhibitors ## Overview ACE inhibitors (Angiotensin-Converting Enzyme inhibitors) are a class of medications primarily used to manage cardiovascular and kidney conditions 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. ## Primary Indications * Hypertension * Heart Failure (HF) with reduced ejection fraction (HFrEF) * Post-Myocardial Infarction (MI) * Diabetic Nephropathy * Chronic Kidney Disease (CKD) with proteinuria ## Adult Dosing Dosing varies significantly by agent and indication. Titration is common to achieve target blood pressure or clinical benefit. * **Hypertension:** Initial doses are typically low, with gradual titration every 1-2 weeks. Maximum doses vary by agent (e.g., lisinopril typically max 40 mg daily, enalapril max 40 mg daily, ramipril max 10 mg daily). * **Heart Failure (HFrEF):** Dosing aims to reach target doses proven in clinical trials (e.g., enalapril target 10 mg BID, lisinopril target 20-40 mg daily, ramipril target 5 mg BID). * **Post-MI:** Generally initiated within 24 hours if no contraindications. (e.g., captopril 6.25 mg TID, titrating to target doses). * **Diabetic Nephropathy/CKD:** Dosing aims to reduce proteinuria, often starting low and titrating upwards as tolerated to achieve target blood pressure or proteinuria reduction. ## Pediatric Dosing Established pediatric dosing exists for some ACE inhibitors, typically for hypertension. * **Enalapril:** 0.08-0.1 mg/kg/dose orally every 12-24 hours; Max 0.58 mg/kg/day or 40 mg/day. * **Lisinopril:** 0.07 mg/kg/dose orally once daily; Max 40 mg/day. * **Captopril:** 0.3 mg/kg/dose orally every 8 hours; Max 3 mg/kg/day or 150 mg/day. Dosing should be individualized and based on clinical response and tolerance. ## Dose Adjustments * **Renal Impairment:** Dose reduction is often necessary, especially in severe renal impairment (eGFR <30 mL/min/1.73 m²). Specific guidance varies by agent. Monitor potassium and renal function closely. * **Hepatic Impairment:** Generally no dose adjustment needed, but caution is advised due to potential for hepatic effects. ## Contraindications * History of angioedema related to prior ACE inhibitor therapy * Concomitant use with aliskiren in patients with diabetes mellitus * Second or third trimester of pregnancy (teratogenic) * Hypersensitivity to the drug class ## Adverse Effects * **Common:** Dry cough (most frequent), dizziness, headache, fatigue, hyperkalemia, hypotension. * **Serious:** Angioedema (potentially life-threatening, particularly of the face, lips, tongue, and larynx), acute kidney injury (especially in bilateral renal artery stenosis), hyperkalemia, elevated liver enzymes. ## Key Drug Interactions * **Potassium-sparing diuretics, potassium supplements, aliskiren, ARBs, heparin, trimethoprim:** Increased risk of hyperkalemia. * **NSAIDs, COX-2 inhibitors:** May reduce antihypertensive efficacy and increase risk of renal dysfunction. * **Diuretics:** Increased risk of hypotension. * **Lithium:** Increased lithium levels and risk of toxicity. * **mTOR inhibitors (e.g., sirolimus, everolimus), DPP-4 inhibitors (e.g., sitagliptin):** Increased risk of angioedema. ## Monitoring * **Baseline:** Renal function (serum creatinine, eGFR), electrolytes (serum potassium), blood pressure. * **During Therapy:** Renal function and serum potassium within 1-2 weeks of initiation or dose increase, and periodically thereafter. Blood pressure. Assess for angioedema and dry cough. ## Clinical Pearls * Dry cough is a common side effect and usually resolves upon discontinuation. * Angioedema is rare but can be fatal; discontinue immediately if suspected. * Initiate at low doses and titrate slowly, especially in patients with volume depletion, renal impairment, or heart failure. * Avoid in pregnancy, particularly the second and third trimesters. * Monitor potassium levels closely, especially in patients with renal impairment or those taking potassium supplements or potassium-sparing diuretics. * Consider switching to an Angiotensin II Receptor Blocker (ARB) if cough is intolerable or angioedema occurs. *** *Disclaimer: This information is intended for clinical professionals. Always consult the most current prescribing information and local protocols for definitive guidance.*