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

Recommended Dosing for Enalapril in 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 or divided doses) based on blood pressure response. For heart failure patients, start with 2.5 mg twice daily and titrate up to 10-20 mg twice daily as tolerated. 1, 2

Dosing in Hypertension

• Initial dose: 5 mg once daily for patients not on diuretics 2
• Initial dose with concurrent diuretic therapy: 2.5 mg once daily under medical supervision for at least two hours (if diuretic cannot be discontinued 2-3 days before starting enalapril) 2
• Maintenance dose: 10-40 mg daily, given as a single dose or divided into two doses 2
• Dose adjustment: If blood pressure control diminishes toward the end of the dosing interval, consider twice daily administration or dose increase 2
• Target systolic blood pressure: <130 mmHg in patients with hypertension, particularly those at increased cardiovascular risk 1

Dosing in Heart Failure

• Initial dose: 2.5 mg twice daily 1, 2
• Titration: Gradually increase dose over a period of a few days to weeks as tolerated 2
• Target dose: 10-20 mg twice daily (maximum daily dose of 40 mg in clinical trials) 1, 2
• Minimum effective dose: At least 50% of target dose (5-10 mg twice daily) should be achieved for clinical benefit 1

Special Populations

Renal Impairment

• Hypertension with renal impairment:

  • Normal to mild impairment (CrCl >30 mL/min): Standard dosing 2
  • Moderate to severe impairment (CrCl ≤30 mL/min): Initial dose 2.5 mg once daily, maximum 40 mg daily 2

• Heart failure with renal impairment:

  • Serum creatinine >1.6 mg/dL: Start with 2.5 mg daily under close medical supervision 2
  • Titrate cautiously to 2.5 mg twice daily, then 5 mg twice daily as tolerated 2

Hyponatremia

• For heart failure patients with hyponatremia (serum sodium <130 mEq/L): Initial dose 2.5 mg daily under close medical supervision 2

Monitoring and Dose Adjustment

• After initial dose, observe patient under medical supervision for at least 2 hours and until blood pressure stabilizes for an additional hour 2
• Monitor blood chemistry (urea, creatinine, potassium) and blood pressure regularly 1
• An increase in creatinine of up to 50% above baseline or to 3 mg/dL (whichever is greater) is acceptable 1
• If excessive increases in creatinine or potassium occur, consider reducing diuretic dose (if no signs of congestion) or discontinuing nephrotoxic drugs 1

Common Pitfalls and Precautions

• First-dose hypotension: More common in volume-depleted patients (e.g., those on high-dose diuretics). If possible, discontinue diuretic 2-3 days before starting enalapril 2
• Hyperkalemia risk: Avoid concurrent use with potassium supplements, potassium-sparing diuretics, or potassium salt substitutes unless specifically indicated 2
• Underdosing: Many patients fail to achieve target doses in clinical practice. Remember that some ACE inhibitor is better than none - aim for at least 50% of target dose 1
• Cough: ACE inhibitor-induced cough rarely requires discontinuation. If troublesome, consider switching to an angiotensin receptor blocker 1
• Drug interactions: Avoid NSAIDs and COX-2 inhibitors when possible as they may reduce enalapril's effectiveness and increase renal risk 1

Enalapril has demonstrated significant benefits in reducing mortality and hospitalizations in heart failure patients and effectively controlling blood pressure in hypertensive patients when properly dosed and monitored 1, 3, 4.