Enalapril Drug Profile

What is Enalapril?

Enalapril is an angiotensin-converting enzyme (ACE) inhibitor medication primarily used to treat high blood pressure and heart failure. As a member of the ACE inhibitor class, it works by blocking an enzyme that narrows blood vessels, helping to lower blood pressure and reduce strain on the heart. Enalapril is available in both oral tablet form and as an injectable formulation for hospital use.

Uses

Enalapril is approved for several cardiovascular conditions:

• Hypertension (high blood pressure): Used as a first-line treatment to lower blood pressure and reduce the risk of heart attack, stroke, and kidney problems
• Heart failure: Helps improve symptoms and survival in patients with reduced heart function by decreasing the heart’s workload
• Left ventricular dysfunction: Prescribed for patients with weakened heart muscle function, even if they don’t have symptoms of heart failure
• Diabetic nephropathy: Helps protect kidney function in diabetic patients by reducing protein loss in urine
• Post-heart attack treatment: Used to prevent further cardiovascular events and improve long-term outcomes following myocardial infarction

How it works

Enalapril blocks the angiotensin-converting enzyme, which normally converts angiotensin I to angiotensin II, a powerful substance that narrows blood vessels and increases blood pressure. By inhibiting this enzyme, enalapril allows blood vessels to relax and widen, reducing blood pressure and making it easier for the heart to pump blood. The medication also reduces the breakdown of bradykinin, a substance that helps dilate blood vessels.

Side effects

Common side effects include:

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• Dry, persistent cough
• Dizziness or lightheadedness
• Fatigue or weakness
• Headache
• Nausea
• Low blood pressure (hypotension)
• Elevated potassium levels (hyperkalemia)
• Rash or skin reactions

Serious side effects requiring immediate medical attention:

• Angioedema (swelling of face, lips, tongue, or throat)
• Severe kidney function decline
• Extremely high potassium levels causing heart rhythm problems
• Severe allergic reactions
• Liver dysfunction or hepatitis

Warnings and precautions

• Pregnancy: Enalapril is contraindicated during pregnancy, especially in the second and third trimesters, as it can cause serious harm to the developing fetus including kidney problems and death
• Kidney disease: Patients with existing kidney problems require careful monitoring and dose adjustments, as ACE inhibitors can worsen kidney function in some cases
• Angioedema history: Individuals with a previous history of angioedema from any cause should avoid enalapril due to increased risk of life-threatening swelling
• Bilateral renal artery stenosis: Patients with narrowing of arteries to both kidneys should not use enalapril as it can cause severe kidney failure
• Surgery and anesthesia: May need to be temporarily discontinued before major surgery due to risk of severe low blood pressure during anesthesia

Interactions

• Potassium supplements and salt substitutes: Can cause dangerous elevation of blood potassium levels when combined with ACE inhibitors
• Diuretics (water pills): May cause excessive blood pressure lowering, especially when starting treatment
• NSAIDs (ibuprofen, naproxen): Can reduce enalapril’s effectiveness and increase risk of kidney problems
• Lithium: Enalapril can increase lithium levels in the blood, potentially causing toxicity
• Aliskiren: Combination increases risk of kidney problems, low blood pressure, and high potassium, especially in diabetic patients
• Gold injections: May cause severe allergic-type reactions when used with ACE inhibitors
• Trimethoprim-sulfamethoxazole: Can increase potassium levels when combined with enalapril
• Diabetes medications: ACE inhibitors may enhance blood sugar-lowering effects, requiring dose adjustments

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Dosage

Typical adult dosages vary based on the condition being treated. For hypertension, the usual starting dose is 5-10 mg once daily, with maintenance doses ranging from 10-40 mg daily, taken as a single dose or divided into two doses. For heart failure, treatment typically begins with 2.5 mg twice daily, gradually increasing to a maintenance dose of 10-20 mg twice daily as tolerated. Patients with kidney impairment require lower starting doses and careful monitoring. Dosage should always be individualized and determined by a healthcare provider based on patient response, kidney function, and blood pressure goals.

Sources: FDA DailyMed drug labels (public domain), BNF, WHO Essential Medicines List. This article is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before starting or stopping any medication.

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