Ace%25252525252525252525252525252525252525252525252525252525252520inhibitors

## Overview Angiotensin-converting enzyme (ACE) inhibitors are a class of medications used primarily to treat cardiovascular conditions, including hypertension, heart failure, and after myocardial infarction. They work by inhibiting the enzyme that converts angiotensin I to angiotensin II, a potent vasoconstrictor, thereby leading to vasodilation and reduced blood pressure. ## Primary Indications * Hypertension * Heart failure (systolic dysfunction) * Left ventricular dysfunction post-myocardial infarction * Diabetic nephropathy (proteinuria) ## Adult Dosing Dosing is highly individualized and depends on the specific agent, indication, and patient response. Titration is usually required. * **Hypertension:** Initial doses vary widely by agent (e.g., lisinopril 5-10 mg PO daily, enalapril 2.5-5 mg PO daily, ramipril 2.5 mg PO daily). Maximum doses also vary (e.g., lisinopril up to 40 mg daily, enalapril up to 40 mg daily, ramipril up to 10 mg daily). * **Heart Failure:** Initial doses are typically lower than for hypertension to avoid hypotension (e.g., lisinopril 2.5-5 mg PO daily, enalapril 2.5-5 mg PO twice daily, ramipril 1.25-2.5 mg PO twice daily). Doses are titrated upwards as tolerated (e.g., lisinopril up to 32.5 mg daily, enalapril up to 20 mg twice daily, ramipril up to 10 mg twice daily). * **Post-Myocardial Infarction:** Initiated within 24 hours in patients with anterior MI or signs of heart failure (e.g., captopril 6.25 mg PO three times daily, enalapril 2.5 mg PO twice daily). Titrated upwards as tolerated. ## Pediatric Dosing Dosing in pediatric patients is not well established for all agents and often requires specialized care. * **Hypertension:** Available data suggest efficacy for some agents, but specific pediatric dosing guidelines may vary by institution and specific drug product. For example, enalapril may be dosed starting at 0.07 mg/kg/day PO, divided twice daily, with titration up to 0.5 mg/kg/day. ## Dose Adjustments * **Renal Impairment:** Dose reduction is typically required. Specific adjustments depend on the individual ACE inhibitor and degree of renal impairment (e.g., creatinine clearance). * **Hepatic Impairment:** Use with caution; dose adjustments may be necessary, especially for prodrugs like enalapril. ## Contraindications * History of angioedema related to previous ACE inhibitor treatment. * Hereditary or idiopathic angioedema. * Concomitant use with aliskiren in patients with diabetes mellitus. * Pregnancy (especially second and third trimesters). ## Adverse Effects * **Dry, persistent cough:** Most common. * **Hypotension:** Especially with initial doses or in volume-depleted patients. * **Hyperkalemia:** Risk increased in renal impairment or with potassium-sparing diuretics. * **Angioedema:** Rare but potentially life-threatening. * **Renal insufficiency:** Can occur, especially in patients with bilateral renal artery stenosis. * **Dizziness, fatigue, headache.** * **Rash, dysgeusia.** ## Key Drug Interactions * **Potassium-sparing diuretics (e.g., spironolactone) and potassium supplements:** Increased risk of hyperkalemia. * **NSAIDs and COX-2 inhibitors:** May reduce antihypertensive effect and increase risk of renal impairment. * **Aliskiren:** Increased risk of hyperkalemia, hypotension, and renal dysfunction; contraindicated in patients with diabetes. * **Lithium:** Increased lithium levels and risk of toxicity. * **Diuretics (especially loop and thiazide):** Increased risk of hypotension. ## Monitoring * **Blood pressure:** Regularly, especially after dose initiation or titration. * **Serum potassium:** Before initiating therapy, within the first month, and periodically thereafter, especially in patients with renal impairment or those on potassium-sparing agents. * **Renal function (serum creatinine and BUN):** Before initiating therapy, within the first month, and periodically thereafter. * **Signs/symptoms of angioedema or hypersensitivity reactions.** ## Clinical Pearls * ACE inhibitors are generally renoprotective in patients with diabetes and proteinuria. * Discontinue ACE inhibitors if angioedema occurs and never re-challenge. * Consider a lower starting dose in elderly patients, those with impaired renal function, or those who are volume-depleted. * Cough is a common dose-limiting side effect and may resolve with discontinuation or switching to an ARB. --- *Disclaimer: This information is intended for clinical use and does not replace comprehensive drug information resources. Always consult the most current prescribing information and relevant clinical guidelines before making treatment decisions.*