Overview
Enalapril is an angiotensin-converting enzyme (ACE) inhibitor used to treat hypertension and heart failure. It works by inhibiting the conversion of angiotensin I to angiotensin II, leading to vasodilation and reduced aldosterone secretion. Clinical trials demonstrate improved survival and reduced hospitalizations in heart failure patients.
Mechanism of Action
Enalapril inhibits angiotensin-converting enzyme (ACE), preventing conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. This results in vasodilation, reduced aldosterone secretion, decreased sodium and water retention, and lowered blood pressure.
Indications
- Hypertension
- Heart failure (to reduce mortality and hospitalizations)
- Asymptomatic left ventricular dysfunction (to delay progression to symptomatic heart failure)
Common Doses
- 2.5 mg
- 5 mg
- 10 mg
- 20 mg
Dosage
Hypertension: Initial dose 5 mg once daily, adjust based on response (usual range 10-40 mg daily in 1-2 divided doses). Heart failure: Start at 2.5 mg once daily, titrate upward to target dose of 10-20 mg daily. Renal impairment requires dosage adjustment.
Contraindications
- Hypersensitivity to enalapril or other ACE inhibitors
- History of angioedema related to ACE inhibitor therapy
- Hereditary or idiopathic angioedema
- Concomitant use with aliskiren in patients with diabetes
- Concomitant use with neprilysin inhibitors (e.g., sacubitril)
Side Effects
- Dizziness
- Headache
- Fatigue
- Cough
- Hypotension
- Hyperkalemia
- Renal dysfunction
- Angioedema
- Rash
- Nausea
- Elevated liver enzymes
Interactions
- Neprilysin inhibitors (increased angioedema risk)
- Aliskiren (avoid in diabetes, increased hyperkalemia and renal impairment risk)
- Diuretics (increased hypotension risk)
- Potassium supplements/potassium-sparing diuretics (increased hyperkalemia risk)
- NSAIDs (may reduce antihypertensive effect and increase renal impairment risk)
- Lithium (increased lithium toxicity risk)
Counseling Points
- Take at same time daily, with or without food
- Report signs of angioedema (swelling of face, lips, tongue, throat) immediately
- Monitor for dizziness, especially with initial doses
- Avoid potassium supplements unless prescribed
- Report persistent dry cough
- Use effective contraception during treatment
- Regular blood pressure monitoring required