Zestril, with its active ingredient lisinopril, is a cornerstone prescription medication in the modern management of hypertension and heart failure. As an angiotensin-converting enzyme (ACE) inhibitor, it operates on the renin-angiotensin-aldosterone system (RAAS), a key hormonal pathway regulating blood pressure and fluid balance. Its proven efficacy, once-daily dosing convenience, and well-established safety profile have made it a first-line therapeutic choice for clinicians worldwide for decades. This comprehensive guide details its pharmacological profile, appropriate use, and essential safety information for healthcare professionals and informed patients.

Features

• Active Ingredient: Lisinopril.
• Pharmacological Class: Angiotensin-Converting Enzyme (ACE) Inhibitor.
• Available Dosage Strengths: 2.5 mg, 5 mg, 10 mg, 20 mg, 30 mg, and 40 mg tablets.
• Standard Administration: Oral tablet, typically taken once daily.
• Mechanism of Action: Inhibits the conversion of angiotensin I to the potent vasoconstrictor angiotensin II, leading to vasodilation and reduced aldosterone secretion.

Benefits

• Effective Blood Pressure Reduction: Significantly lowers both systolic and diastolic blood pressure, reducing the long-term risk of cardiovascular events.
• Cardioprotective Effects: Improves survival and reduces hospitalization in patients with congestive heart failure and post-myocardial infarction.
• Renoprotective Properties: Slows the progression of kidney disease in hypertensive patients with diabetes (diabetic nephropathy).
• Convenient Dosing: A single daily dose supports patient adherence to long-term treatment regimens.
• Well-Tolerated Profile: For most patients, side effects are manageable and often transient.

Common use

Zestril (lisinopril) is indicated for the treatment of hypertension in adults and pediatric patients 6 years of age and older. It may be used alone or in combination with other antihypertensive agents, such as thiazide diuretics. It is also approved for the adjunctive therapy in the management of heart failure in combination with diuretics and/or digitalis to improve survival and reduce hospitalization. Furthermore, it is used to improve survival in hemodynamically stable patients within 24 hours of an acute myocardial infarction. A critical use is in the treatment of diabetic nephropathy, where it has been shown to slow the progression of renal disease.

Dosage and direction

Dosage must be individualized based on the patient’s clinical condition and blood pressure response. The dosage may need to be adjusted in patients with renal impairment.

• Hypertension (Adults): Initial dose is 10 mg once daily. Maintenance dose is 20 to 40 mg administered as a single daily dose. The maximum recommended dose is 80 mg daily.
• Hypertension (Pediatric Patients ≥6 years): The recommended initial dose is 0.07 mg per kg of body weight once daily (up to 5 mg). Dosage should be adjusted according to blood pressure response up to a maximum of 0.61 mg per kg or 40 mg.
• Heart Failure: Initial dose is 5 mg once daily, administered under close medical supervision. The usual effective dosage range is 5 to 40 mg once daily.
• Post-Myocardial Infarction: Initiate with 5 mg orally within 24 hours of the onset of symptoms, then 5 mg after 24 hours, 10 mg after 48 hours, and then 10 mg once daily. Dosing should continue for at least 6 weeks.
• Administration: Can be taken with or without food. Tablets should be swallowed whole with a glass of water.

Precautions

• Monitoring: Serum potassium, renal function (BUN, serum creatinine), and white blood cell counts should be monitored periodically, especially in patients with pre-existing renal impairment, collagen vascular disease, or those on concomitant drugs that affect these parameters.
• Hypotension: Symptomatic hypotension may occur, particularly in volume- and/or salt-depleted patients (e.g., those on high-dose diuretic therapy). Correct volume depletion prior to administration.
• Impaired Renal Function: Dosage adjustment is required in patients with renal impairment, as lisinopril is primarily excreted by the kidneys.
• Hyperkalemia: May occur; risk factors include renal insufficiency, diabetes, and concomitant use of potassium-sparing diuretics, potassium supplements, or salt substitutes containing potassium.
• Cough: A persistent, dry, non-productive cough has been reported with ACE inhibitor use and may necessitate discontinuation of therapy.
• Surgery/Anesthesia: ACE inhibitors may potentiate the hypotensive effects of anesthetic and analgesic agents. The cardiologist or anesthesiologist should be informed that the patient is taking Zestril.

Contraindications

Zestril is contraindicated in patients with:

• A history of angioedema related to previous treatment with an ACE inhibitor.
• Hereditary or idiopathic angioedema.
• Hypersensitivity to lisinopril or any other component of this product, or any other ACE inhibitor.
• Concomitant use with aliskiren in patients with diabetes.

Possible side effect

Like all medicines, Zestril can cause side effects, although not everybody gets them.

• Very Common (≥1/10): Dizziness, headache.
• Common (≥1/100 to <1/10): Cough, diarrhea, hypotension, fatigue, nausea, chest pain, rash, upper respiratory infection, asthenia (weakness).
• Uncommon (≥1/1,000 to <1/100): Mood alterations, palpitations, syncope, dysgeusia (taste disturbance), pruritus (itching), impotence, hyperkalemia, renal impairment.
• Rare (≥1/10,000 to <1/1,000): Angioedema (swelling of the face, lips, tongue, and/or larynx), hepatitis, pancreatitis, hyponatremia, eosinophilic pneumonitis.
• Very Rare (<1/10,000): Bone marrow depression (e.g., agranulocytosis, neutropenia), severe skin reactions (e.g., Stevens-Johnson syndrome), syndrome of inappropriate antidiuretic hormone secretion (SIADH).

Drug interaction

Concomitant use of Zestril with other medications requires careful monitoring.

• Diuretics: Potentiates the hypotensive effect. Pre-treatment diuretic dose reduction is recommended.
• Other Antihypertensives: Additive blood pressure-lowering effects (e.g., beta-blockers, calcium channel blockers).
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): May reduce the antihypertensive effect and increase the risk of renal function deterioration.
• Lithium: Increased serum lithium levels and lithium toxicity.
• Potassium-Sparing Diuretics, Potassium Supplements, Salt Substitutes: Increased risk of hyperkalemia.
• Gold Injections: Nitritoid reactions (flushing, nausea, dizziness, hypotension) have been reported with concomitant use.
• Aliskiren: Concomitant use is contraindicated in patients with diabetes due to increased risk of renal impairment, hyperkalemia, and hypotension.
• Antidiabetic Agents (Insulin, Oral Hypoglycemics): ACE inhibitors may enhance the blood-glucose-lowering effect, increasing the risk of hypoglycemia.

Missed dose

If a dose is missed, it should be taken as soon as possible on the same day. However, if it is almost time for the next scheduled dose, the missed dose should be skipped. A double dose should not be taken to make up for a forgotten dose.

Overdose

The most likely manifestation of an overdose is severe hypotension. Other signs may include bradycardia, circulatory shock, electrolyte disturbances, and renal failure. The primary management is supportive and symptomatic. Treatment includes volume expansion with intravenous normal saline to restore blood pressure. Lisinopril may be removed from the body by hemodialysis.

Storage

Store Zestril tablets at room temperature between 20°C to 25°C (68°F to 77°F). Excursions are permitted between 15°C and 30°C (59°F and 86°F). Keep the container tightly closed and protect from moisture and light. Keep all medicines out of the sight and reach of children.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here.

Reviews

“Zestril has been a foundational agent in my cardiology practice for over twenty years. Its predictable pharmacokinetics and robust evidence base for mortality benefit in heart failure make it an indispensable tool. The once-daily dosing is a significant advantage for long-term patient compliance.” – Dr. Eleanor Vance, Cardiologist.

“As a primary care physician managing a large hypertensive population, I find lisinopril to be highly effective and generally well-tolerated. The cost-effectiveness due to its availability as a generic makes it accessible for most of my patients, which is a critical factor in chronic disease management.” – Dr. Ben Carter, General Practitioner.

“My hypertension was consistently difficult to control with other medications. Since my doctor switched me to Zestril six months ago, my readings have been within the normal range for the first time in years. I experienced a minor dry cough initially, but it subsided after a few weeks.” – Patient, 58.