What is the recommended dosing for Benazepril (Angiotensin-Converting Enzyme (ACE) inhibitor)?

Benazepril Dosing Recommendations

For adults not on diuretics, start benazepril at 10 mg once daily, with a usual maintenance range of 20-40 mg per day administered as a single dose or divided into two equal doses. 1

Standard Adult Dosing

• Initial dose: 10 mg once daily for patients not receiving a diuretic 1
• Maintenance dose: 20-40 mg per day, given as a single dose or in two equally divided doses 1
• Maximum studied dose: 80 mg daily provides increased response, though experience at this dose is limited 1
• Divided dosing consideration: The twice-daily regimen is more effective at controlling trough (pre-dosing) blood pressure than the same total dose given once daily 1

Special Populations

Patients on Diuretics

• Starting dose: 5 mg once daily when initiating benazepril in a patient already on a diuretic 1
• If blood pressure remains uncontrolled with benazepril alone, add a low dose of diuretic 1

Renal Impairment

• For GFR <30 mL/min/1.73 m² (serum creatinine >3 mg/dL): Start at 5 mg once daily 1
• Titrate upward until blood pressure is controlled or to a maximum of 40 mg daily 1
• Monitor closely as benazepril can worsen renal function 1

Pediatric Patients (≥6 years)

• Starting dose: 0.2 mg/kg once daily 1
• Titration: Increase as needed to 0.6 mg/kg once daily 1
• Maximum: Doses above 0.6 mg/kg or 40 mg daily have not been studied 1
• Not recommended in children <6 years or with GFR <30 mL/min/1.73 m² 1

Clinical Pharmacology

• Onset: Blood pressure lowering begins within 1 hour 1
• Peak effect: Achieved 2-4 hours after dosing 1
• Duration: Antihypertensive effect persists for 24 hours 1
• Trough efficacy: Once-daily doses of 20-80 mg decrease blood pressure at 24 hours by approximately 6-12 mmHg systolic and 4-7 mmHg diastolic, representing about 50% of peak effect 1

Dose-Response Relationship

• Minimal effective dose: 10 mg once daily 1, 2
• Optimal dose: 20 mg once daily provides clinically important blood pressure reduction 2
• Higher doses: 40 mg and 80 mg provide small additional reductions beyond 20 mg 1, 2
• The dose-response curve shows continued benefit across the 10-80 mg range, particularly for morning trough blood pressure control 1

Combination Therapy

• With thiazide diuretics: Produces greater blood pressure lowering than either agent alone 1
• Benazepril blocks the renin-angiotensin-aldosterone axis, reducing potassium loss associated with diuretics 1
• Combinations with hydrochlorothiazide or nifedipine achieve greater reductions and may be suitable for more severe hypertension 3

Monitoring Requirements

• Blood pressure: Check within 1-2 weeks after initiation or dose changes 4
• Renal function: Monitor serum creatinine/eGFR at least annually, or more frequently in patients with renal impairment 5
• Potassium levels: Monitor at least annually, particularly in patients with renal dysfunction or those on potassium supplements 5, 4
• Watch for: Hypotension (especially in volume-depleted patients), hyperkalemia, and acute kidney injury 4

Important Caveats

• Timing flexibility: Benazepril can be taken any time of day, with or without food 6
• Drug interactions: No clinically important interactions with digoxin, warfarin, naproxen, cimetidine, hydrochlorothiazide, furosemide, propranolol, atenolol, or chlorthalidone 6
• Contraindication: ACE inhibitors are contraindicated during pregnancy 5
• Renal effects: Increases renal blood flow without affecting glomerular filtration rate in normal volunteers 1