Zestril

Zestril (lisinopril) is an angiotensin-converting enzyme (ACE) inhibitor prescribed for the management of hypertension, heart failure, and post-myocardial infarction care. It works by inhibiting the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in vasodilation and reduced blood pressure. This medication represents a cornerstone in cardiovascular pharmacotherapy, offering both hemodynamic benefits and organ-protective effects. Clinical evidence supports its role in improving survival rates and reducing hospitalizations in specific cardiac patient populations.

Features

• Active ingredient: Lisinopril
• Drug class: Angiotensin-converting enzyme (ACE) inhibitor
• Available in tablet formulations: 2.5 mg, 5 mg, 10 mg, 20 mg, 30 mg, 40 mg
• Standard once-daily dosing regimen
• Bioavailability: Approximately 25%
• Elimination half-life: 12 hours
• Primarily renal excretion pathway

Benefits

• Achieves significant reduction in systolic and diastolic blood pressure measurements
• Decreases afterload on the heart, improving cardiac output in heart failure patients
• Demonstrates nephroprotective properties in diabetic patients with proteinuria
• Reduces mortality risk following acute myocardial infarction
• Provides long-term cardiovascular risk modification
• May slow progression of left ventricular hypertrophy

Common use

Zestril is primarily indicated for the treatment of hypertension, either as monotherapy or in combination with other antihypertensive agents. It is also approved for the management of congestive heart failure, often as adjunctive therapy with diuretics and digitalis. Additionally, it is used in the early treatment of hemodynamically stable patients within 24 hours of acute myocardial infarction to improve survival. Off-label uses may include diabetic nephropathy and chronic kidney disease management.

Dosage and direction

The initial dosage for hypertension typically ranges from 2.5-10 mg once daily, with maintenance doses of 20-40 mg daily. For heart failure, starting doses are usually 2.5-5 mg daily, titrated upward as tolerated. Post-myocardial infarction patients may begin with 5 mg within 24 hours of symptoms, followed by 5 mg after 24 hours, then 10 mg daily. Dosage adjustments are necessary in renal impairment, with creatinine clearance below 30 mL/min requiring reduced initial dosing. Administration should occur at approximately the same time each day, with or without food.

Precautions

Patients should be monitored for hypotension, especially during initial dosing and titration periods. Renal function and serum potassium levels require regular assessment, particularly in patients with pre-existing renal impairment or those taking potassium-sparing diuretics. Angioedema may occur at any time during treatment, requiring immediate discontinuation. Caution is advised in patients with collagen vascular diseases or those receiving immunosuppressive therapy due to increased risk of neutropenia/agranulocytosis.

Contraindications

Zestril is contraindicated in patients with a history of angioedema related to previous ACE inhibitor therapy. Additional contraindications include hypersensitivity to lisinopril or any component of the formulation and concomitant use with aliskiren in patients with diabetes. The medication is also contraindicated during the second and third trimesters of pregnancy due to potential fetal injury and mortality.

Possible side effect

Common adverse reactions include dizziness (6-12%), headache (5-6%), cough (3-9%), and fatigue (3-5%). Less frequently observed effects include orthostatic hypotension, rash, gastrointestinal disturbances, and hyperkalemia. Serious but rare side effects may include angioedema, neutropenia/agranulocytosis, hepatic failure, and pancreatitis. Renal function deterioration may occur in susceptible individuals, particularly those with renal artery stenosis.

Drug interaction

Significant interactions occur with potassium supplements, potassium-sparing diuretics, and salt substitutes containing potassium, increasing hyperkalemia risk. Nonsteroidal anti-inflammatory drugs may reduce the antihypertensive effects of Zestril and increase renal impairment risk. Concurrent use with lithium may increase lithium concentrations and toxicity risk. Diuretics may potentiate the hypotensive effects, particularly following the first dose. Dual blockade of the renin-angiotensin system with ARBs or aliskiren increases adverse event risk.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, the missed dose should be skipped, and the regular dosing schedule resumed. Patients should not double the dose to make up for a missed administration. Consistent daily dosing is important for maintaining stable blood pressure control.

Overdose

Symptoms of overdose may include severe hypotension, bradycardia, circulatory shock, electrolyte disturbances, and renal failure. Management involves supportive care with volume expansion with normal saline to maintain blood pressure. Hemodialysis may be effective in removing lisinopril from the systemic circulation. Bradycardia may require atropine administration, and vasopressors may be necessary in cases of profound hypotension unresponsive to volume expansion.

Storage

Store at controlled room temperature between 20-25°C (68-77°F). Protect from moisture and light. Keep in the original container with the lid tightly closed. Do not store in bathroom areas where moisture levels may be higher. Keep all medications out of reach of children and pets. Properly discard any expired or unused medication according to local regulations.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Individual patient responses to medication may vary. Healthcare professionals should exercise clinical judgment when prescribing, considering individual patient factors, contraindications, and potential adverse effects. Patients should not initiate, discontinue, or change dosage without consulting their healthcare provider. Full prescribing information should be reviewed before administration.

Reviews

Clinical trials demonstrate Zestril’s efficacy in reducing blood pressure by approximately 8-10 mmHg systolic and 6-7 mmHg diastolic compared to placebo. The SOLVD treatment trial showed a 16% reduction in mortality and a 26% decrease in hospitalization for heart failure in patients receiving lisinopril. The GISSI-3 trial indicated a 11% reduction in mortality at 6 weeks post-myocardial infarction. Real-world evidence supports these findings, though individual responses vary based on comorbidities, concomitant medications, and genetic factors affecting the renin-angiotensin system.