What is the recommended dosing for Enalapril (Angiotensin-Converting Enzyme inhibitor) in patients with hypertension or heart failure?

Enalapril Dosing for Hypertension and Heart Failure

For patients with hypertension, enalapril should be initiated at 5 mg once daily and titrated to 10-40 mg daily (single dose or divided twice daily), while heart failure patients should start at 2.5 mg twice daily and titrate to 10-20 mg twice daily as tolerated. 1

Dosing for Hypertension

Initial Dosing

• Standard initial dose: 5 mg once daily for patients not on diuretics 1
• With concurrent diuretic therapy: 2.5 mg once daily under medical supervision for at least two hours and until blood pressure stabilizes for an additional hour 1
• Renal impairment:
  • Normal renal function (>80 mL/min): 5 mg daily
  • Mild impairment (30-80 mL/min): 5 mg daily
  • Moderate to severe impairment (≤30 mL/min): 2.5 mg daily 1

Maintenance and Target Dosing

• Usual dosage range: 10-40 mg per day (single dose or divided twice daily) 1
• Titration: Adjust according to blood pressure response 1
• Dosing frequency: If once-daily dosing shows diminishing effect toward end of dosing interval, consider twice-daily administration 1
• Target blood pressure: <130/80 mmHg for patients at increased cardiovascular risk 2

Dosing for Heart Failure

Initial Dosing

• Starting dose: 2.5 mg twice daily 2, 1
• First dose monitoring: Observe under medical supervision for at least two hours and until blood pressure stabilizes for an additional hour 1
• Diuretic management: If possible, reduce dose of any concomitant diuretic to minimize risk of hypotension 1

Maintenance and Target Dosing

• Titration: Increase dose gradually over a period of a few days or weeks as tolerated 1
• Target dose: 10-20 mg twice daily 2, 1
• Maximum daily dose: 40 mg in divided doses (used in clinical trials) 2, 1
• Mean dose achieved in clinical trials: 16.6 mg daily 2

Dosing for Asymptomatic Left Ventricular Dysfunction

• Starting dose: 2.5 mg twice daily 1
• Target dose: 20 mg daily in divided doses 1
• Monitoring: Same as for heart failure patients 1

Practical Considerations for Dosing

Monitoring During Titration

• Blood pressure: Monitor regularly, especially during dose adjustments
• Renal function: Check before initiation, 1-2 weeks after starting therapy, and after each dose increase
• Electrolytes: Monitor potassium levels, especially if combined with potassium-sparing diuretics 1

Common Side Effects to Monitor

• Hypotension: May occur after initial dose, especially in volume-depleted patients
• Hyperkalemia: Risk increases with renal impairment or concomitant potassium-sparing medications
• Cough: Dry, persistent cough is a class effect of ACE inhibitors
• Renal function deterioration: Particularly in patients with bilateral renal artery stenosis 1

Special Populations

• Dialysis patients: 2.5 mg on dialysis days with adjustment on non-dialysis days based on blood pressure response 1
• Elderly patients: No specific dose adjustment required, but monitor closely due to potential for greater sensitivity to drug effects

Clinical Efficacy

• In hypertension studies, enalapril 5-40 mg daily reduced blood pressure from baseline 147/98 mmHg to 126/82 mmHg 3
• Most patients (98%) achieved target diastolic blood pressure <90 mmHg by the end of titration period 3
• In heart failure, enalapril improves cardiac performance by reducing both preload and afterload 4

By following these dosing recommendations, clinicians can optimize the benefits of enalapril therapy while minimizing potential adverse effects in patients with hypertension or heart failure.