Zestril (lisinopril) is an angiotensin-converting enzyme (ACE) inhibitor prescribed for the management of hypertension, heart failure, and post-myocardial infarction care. As a cornerstone therapy in cardiovascular medicine, it works by inhibiting the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, thereby promoting vasodilation and reducing the heart’s workload. Its proven efficacy in large-scale clinical trials and well-established safety profile make it a first-line choice for physicians seeking to mitigate cardiovascular risk and improve long-term patient outcomes. This medication requires a prescription and should be taken under strict medical supervision.

Features

• Active Ingredient: Lisinopril
• Drug Class: Angiotensin-converting enzyme (ACE) inhibitor
• Available Strengths: 2.5 mg, 5 mg, 10 mg, 20 mg, 30 mg, 40 mg tablets
• Administration: Oral, once-daily dosing
• Onset of Action: Peak plasma concentrations within 7 hours
• Half-life: Approximately 12 hours
• Bioavailability: ~25%, not significantly affected by food

Benefits

• Effectively lowers systolic and diastolic blood pressure, reducing the risk of stroke, myocardial infarction, and kidney damage.
• Improves survival rates and functional capacity in patients with congestive heart failure when used as part of a comprehensive treatment plan.
• Provides renal protective effects in hypertensive patients with type 2 diabetes and microalbuminuria.
• Demonstrates a favorable side effect profile compared to many other antihypertensive agents when appropriately dosed.
• Offers convenient once-daily dosing that supports medication adherence and consistent therapeutic coverage.
• May reduce left ventricular hypertrophy and improve endothelial function beyond blood pressure control alone.

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 heart failure to improve survival and reduce hospitalization when added to conventional therapy including diuretics and digitalis. Additionally, Zestril is used in stable patients who have experienced acute myocardial infarction to improve survival when started within 24 hours of symptoms. Off-label uses may include diabetic nephropathy, chronic kidney disease progression delay, and migraine prophylaxis, though these applications require careful physician evaluation.

Dosage and direction

For hypertension, the initial dose is typically 10 mg once daily, which may be increased to a maintenance dose of 20-40 mg daily based on blood pressure response. For heart failure, starting dose is 2.5-5 mg once daily, titrated upward as tolerated to a target of 20-40 mg daily. Post-myocardial infarction patients may begin with 5 mg within 24 hours of symptoms, followed by 5 mg after 24 hours, 10 mg after 48 hours, and then 10 mg daily for six weeks. Dosage adjustments are necessary in renal impairment: for creatinine clearance 10-30 mL/min, initial dose is 2.5-5 mg daily; below 10 mL/min, initial dose is 2.5 mg daily. Tablets should be swallowed whole with water, with or without food, at approximately the same time each day.

Precautions

Patients should be monitored for hypotension, especially during initial dosing and titration periods. Renal function and serum potassium should be assessed before initiation and periodically during therapy. Angioedema may occur at any time during treatment, requiring immediate discontinuation if involving the face, lips, tongue, glottis, or larynx. Use with caution in patients with renal artery stenosis, collagen vascular diseases, or those undergoing major surgery. Caucasian patients may have increased risk of angioedema compared to other racial groups. Patients should be advised to avoid potassium supplements or salt substitutes containing potassium unless specifically directed by their physician.

Contraindications

Zestril is contraindicated in patients with a history of angioedema related to previous ACE inhibitor treatment. It should not be used in patients with hereditary or idiopathic angioedema. Concomitant use with aliskiren-containing products is contraindicated in patients with diabetes. Additional contraindications include hypersensitivity to lisinopril or any component of the formulation and concomitant use with sacubitril/valsartan. The drug is contraindicated during the second and third trimesters of pregnancy due to potential fetal injury and death.

Possible side effect

Common adverse reactions (≥1%) include dizziness (12%), headache (5%), cough (3-9%), fatigue (3%), diarrhea (3%), and upper respiratory symptoms (2%). Less frequent side effects include orthostatic hypotension (2%), rash (1-2%), impotence (1%), and nausea (2%). Serious but rare adverse events include angioedema (0.1-0.7%), hyperkalemia (2-5%), renal impairment (1-2%), neutropenia/agranulocytosis, and hepatic failure. The characteristic dry, persistent cough may develop in 5-20% of patients, often leading to discontinuation.

Drug interaction

Significant interactions occur with potassium-sparing diuretics, potassium supplements, and salt substitutes, increasing hyperkalemia risk. Concurrent use with NSAIDs may reduce antihypertensive effects and increase renal impairment risk. Lithium levels may increase with ACE inhibitor coadministration. Dual blockade of the renin-angiotensin system with ARBs or aliskiren increases adverse event risk. Gold injections may cause nitritoid reactions. Diabetic patients receiving insulin or oral hypoglycemics may experience enhanced hypoglycemic effects. Alcohol, barbiturates, or narcotics may potentiate hypotensive effects.

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 dose. Consistency in dosing is important for maintaining stable blood pressure control, so establishing a routine (such as taking the medication with a daily activity) is recommended to minimize missed doses.

Overdose

Lisinopril overdose may manifest as severe hypotension, which can progress to shock. Bradycardia, electrolyte disturbances, and renal failure may also occur. Management includes supportive care with volume expansion with normal saline to maintain blood pressure. Hemodialysis may be effective in removing lisinopril from the circulation. Patients should be monitored in an intensive care setting with continuous blood pressure and ECG monitoring. Vasopressors may be required in refractory cases of hypotension.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) in the original container with the lid tightly closed. Protect from moisture and light. Keep out of reach of children and pets. Do not use if tablets appear discolored, show signs of deterioration, or are beyond the expiration date printed on the packaging. Do not transfer to other containers as this may affect stability. Proper disposal of unused medication should follow local regulations, typically through medication take-back programs.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Zestril is a prescription medication that should be used only under the supervision of a qualified healthcare professional. Individual response to medication may vary, and only your physician can determine the appropriate treatment based on your specific medical condition, other medications, and overall health status. Never adjust your dosage or discontinue medication without consulting your healthcare provider.

Reviews

Clinical studies demonstrate Zestril’s efficacy with meta-analyses showing approximately 8-10 mmHg reduction in systolic and 4-6 mmHg reduction in diastolic blood pressure at 10-20 mg daily doses. In the SOLVD treatment trial, lisinopril reduced mortality by 16% in heart failure patients. The GISSI-3 trial showed a 11% reduction in mortality when started early after myocardial infarction. Patient satisfaction surveys indicate good tolerability, though cough remains a frequent reason for discontinuation. Real-world evidence supports its effectiveness in diverse populations when appropriately prescribed and monitored.