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Drugs, Supplies and Delivery
Enalapril
Enalapril is an angiotensin-converting enzyme (ACE) inhibitor widely prescribed for hypertension, heart failure, and diabetic nephropathy. Renowned for its efficacy in reducing cardiovascular morbidity and mortality, enalapril is a cornerstone in managing high blood pressure and related conditions. This article synthesizes evidence from the British National Formulary (BNF), Lippincott Textbook of Pharmacology, and Lange Basic & Clinical Pharmacology to outline its pharmacology, clinical applications, and safety profile.
Enalapril inhibits angiotensin-converting enzyme (ACE), preventing the conversion of angiotensin I to angiotensin II. This results in:
- Vasodilation: Reduced angiotensin II decreases systemic vascular resistance.
- Aldosterone Suppression: Lowers sodium/water retention and potassium excretion, aiding blood pressure control.
- Bradykinin Accumulation: Increased bradykinin levels enhance vasodilation but may cause cough and angioedema (Lippincott Textbook of Pharmacology).
Enalapril’s effects are sustained due to its long half-life, allowing once- or twice-daily dosing (Lange Basic & Clinical Pharmacology).
- Hypertension:
- First-line monotherapy or combined with diuretics/calcium channel blockers.
- Heart Failure:
- Improves survival and symptoms in reduced ejection fraction (e.g., SOLVD trial).
- Diabetic Nephropathy:
- Slows progression of kidney disease in type 1 diabetes (BNF).
- Post-Myocardial Infarction (MI):
- Prevents ventricular remodeling and reduces mortality.
- Hypertension:
- Adults: 5 mg once daily, titrated to 10–20 mg daily (max 40 mg/day).
- Elderly: Start at 2.5 mg daily to avoid hypotension.
- Heart Failure: 2.5 mg once daily, increased to 10–20 mg twice daily.
- Renal Impairment:
- eGFR 30–60 mL/min: Max 10 mg daily.
- eGFR <30 mL/min: Max 5 mg daily (BNF).
- Dry cough (up to 20% of patients), dizziness, headache.
- Hyperkalemia, mild renal impairment.
Serious (Rare):
- Angioedema: Facial/tongue swelling (immediate discontinuation required).
- Acute Kidney Injury: Monitor creatinine in renal impairment.
- Fetal Toxicity: Category D (contraindicated in second/third trimesters) (Lange Basic & Clinical Pharmacology).
- Contraindications:
- History of angioedema, bilateral renal artery stenosis, pregnancy.
- Concomitant use with aliskiren in diabetic patients.
- Monitoring:
- Serum potassium, renal function, and blood pressure.
- Avoid in hypovolemia (risk of first-dose hypotension).
- Pregnancy/Lactation:
- Lactation: Excreted in breast milk; avoid (BNF).
- Potassium-Sparing Diuretics (e.g., spironolactone): Increased hyperkalemia risk.
- NSAIDs (e.g., ibuprofen): Reduced antihypertensive efficacy; nephrotoxicity risk.
- Lithium: Elevated lithium levels (monitor toxicity).
- Aliskiren: Avoid combination in diabetes (increased renal impairment risk) (Lippincott Textbook of Pharmacology).
- Generic: Enalapril maleate.
- Brand Names: Vasotec®, Innovace®, Renitec®.
- Combination Products: Enalapril/hydrochlorothiazide (e.g., Vaseretic®).
