Ace%25252525252520inhibitors

# ACE Inhibitors (e.g., Lisinopril, Enalapril, Ramipril) ## Overview Angiotensin-Converting Enzyme (ACE) inhibitors block the conversion of Angiotensin I to Angiotensin II, a potent vasoconstrictor, reducing systemic vascular resistance and aldosterone secretion. They are cornerstone therapies in hypertension, heart failure (HFrEF), and chronic kidney disease. ## Primary Indications * Hypertension * Heart failure with reduced ejection fraction (HFrEF) * Post-myocardial infarction (MI) * Diabetic nephropathy / Proteinuric chronic kidney disease (CKD) ## Adult Dosing *(Examples provided for representative agents)* * **Lisinopril:** * Hypertension: Initial 10 mg daily; maintenance 20–40 mg daily. Max 80 mg/day. * HFrEF: Initial 2.5–5 mg daily; target 20–40 mg daily. * **Enalapril:** * Hypertension: Initial 5 mg daily; maintenance 10–40 mg/day (divided or daily). * HFrEF: Initial 2.5 mg twice daily; target 10–20 mg twice daily. * **Ramipril:** * Hypertension: Initial 2.5 mg daily; maintenance 2.5–20 mg/day (divided or daily). ## Pediatric Dosing *Dosing is weight-based and highly variable by indication and agent. Consult institutional protocols or specialized references (e.g., Harriet Lane).* * **Enalapril:** Hypertension; starting dose 0.08 mg/kg once daily. Max 0.6 mg/kg (or 40 mg/day). * **Lisinopril:** Hypertension; starting dose 0.07 mg/kg once daily. Max 0.6 mg/kg (or 40 mg/day). ## Dose Adjustments * **Renal Impairment:** Reduce initial doses and titrate cautiously if CrCl < 30 mL/min. * **Hepatic Impairment:** Use caution; may require dose reduction especially with prodrugs (e.g., Enalapril) that require hepatic conversion to active metabolites (Enalaprilat). * **Volume Depletion:** Temporarily discontinue diuretics 2–3 days prior to initiating to prevent profound hypotension. ## Contraindications * History of angioedema (hereditary, idiopathic, or drug-induced). * Concomitant use with Aliskiren in patients with diabetes. * Pregnancy (Category D: causes fetal morbidity/mortality; discontinue immediately if pregnancy is detected). * Bilateral renal artery stenosis (may precipitate acute renal failure). ## Adverse Effects * **Common:** Dry, hacking cough (due to bradykinin accumulation), hyperkalemia, headache, dizziness, fatigue. * **Serious:** Angioedema (life-threatening airway obstruction), acute renal failure, hyperkalemia, agranulocytosis (rare). ## Key Drug Interactions * **Potassium Supplements/Potassium-sparing Diuretics:** High risk of severe hyperkalemia. * **NSAIDs:** May reduce antihypertensive effect and increase risk of acute kidney injury through altered renal hemodynamics. * **Lithium:** May reduce renal clearance and increase lithium toxicity risk. * **Sacubitril/Valsartan:** Do not use concomitantly; ensure a 36-hour washout period to prevent increased risk of angioedema. ## Monitoring * **Baseline/Follow-up:** Serum creatinine (SCr), blood urea nitrogen (BUN), and serum potassium levels. * **Blood Pressure:** Monitor for orthostasis and hypotension. * **Emergency:** Monitor for signs of angioedema (swelling of face, lips, tongue, glottis). ## Clinical Pearls * **"Start Low, Go Slow":** Especially in heart failure patients or those on volume-depleting therapy. * **Dry Cough:** If persistent and bothersome, switch to an Angiotensin II Receptor Blocker (ARB), as they do not inhibit bradykinin degradation. * **AKI Risk:** A temporary increase in SCr (up to 30%) is often expected and acceptable after initiation, but requires clinical review if the rise is steeper. *** **Educational Disclaimer:** This information is for educational purposes only. Dosing and clinical management should be verified against current institutional protocols, updated clinical guidelines (e.g., ACC/AHA), and the latest package inserts before prescribing. Consult a licensed pharmacist or healthcare provider for specific clinical decisions.