Lisinopril

Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor prescribed primarily 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, thereby promoting vasodilation and reducing peripheral arterial resistance. This mechanism not only lowers blood pressure but also decreases the heart’s workload, making it a cornerstone therapy in cardiovascular medicine. Clinical evidence supports its role in improving survival rates in heart failure patients and reducing morbidity following acute myocardial events.

Features

• Active ingredient: Lisinopril
• Drug class: Angiotensin-converting enzyme (ACE) inhibitor
• Available formulations: Oral tablets (2.5 mg, 5 mg, 10 mg, 20 mg, 30 mg, 40 mg)
• Bioavailability: Approximately 25%, with peak plasma concentrations reached within 7 hours
• Half-life: 12 hours, permitting once-daily dosing in most patients
• Metabolism: Not significantly metabolized; excreted unchanged in urine
• FDA-approved indications: Hypertension, heart failure, acute myocardial infarction

Benefits

• Effectively lowers systolic and diastolic blood pressure, reducing cardiovascular risk
• Improves survival and functional capacity in patients with congestive heart failure
• Provides nephroprotective effects in diabetic patients with proteinuria
• Reduces mortality when administered within 24 hours of acute myocardial infarction
• Once-daily dosing supports medication adherence and consistent therapeutic coverage
• Well-tolerated profile with a lower incidence of metabolic side effects compared to other antihypertensives

Common use

Lisinopril is primarily indicated for the treatment of hypertension, either as monotherapy or in combination with other antihypertensive agents. It is also used in the management of symptomatic heart failure, typically as adjunctive therapy with diuretics and/or beta-blockers. Additionally, lisinopril is administered to hemodynamically stable patients within 24 hours of acute myocardial infarction to improve survival and reduce the incidence of heart failure. Off-label uses may include the delay of diabetic nephropathy progression and management of certain forms of secondary hypertension.

Dosage and direction

For hypertension, the initial dose is typically 10 mg once daily, which may be adjusted based on therapeutic response up to a maximum of 40 mg daily. In heart failure, treatment usually begins with 2.5–5 mg once daily under close medical supervision, with gradual titration to a target maintenance dose of 20–40 mg daily. For post-myocardial infarction management, an initial 5 mg dose is given within 24 hours of symptom onset, followed by 5 mg after 24 hours, 10 mg after 48 hours, and then 10 mg daily for 6 weeks. Dosage adjustments are necessary in patients with renal impairment—creatinine clearance <30 mL/min typically requires reduced initial dosing. Administration should occur at approximately the same time each day, with or without food, though consistent timing is recommended for stable pharmacokinetics.

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, diabetes, or those using potassium-sparing diuretics. Angioedema, though rare, may occur at any time during treatment and requires immediate discontinuation. A persistent dry cough may develop in some patients, typically resolving upon discontinuation. Lisinopril should be used cautiously in patients with collagen vascular disease or those receiving immunosuppressive therapy due to increased risk of neutropenia/agranulocytosis. Pregnancy must be avoided during treatment due to potential fetal harm.

Contraindications

Lisinopril is contraindicated in patients with a history of angioedema related to previous ACE inhibitor therapy or hereditary/idiopathic angioedema. It should not be used in patients with bilateral renal artery stenosis or solitary kidney with renal artery stenosis. Concomitant use with aliskiren in patients with diabetes is contraindicated. Lisinopril is pregnancy Category D and is contraindicated during all trimesters due to risk of fetal injury and death. Hypersensitivity to any ACE inhibitor component represents an absolute contraindication.

Possible side effect

Common adverse reactions include dizziness (6–12%), headache (5–9%), persistent dry cough (3–10%), and fatigue (3–5%). Gastrointestinal effects such as nausea (3–5%) and diarrhea (2–4%) may occur. Orthostatic hypotension affects approximately 2–4% of patients, particularly during initial therapy. Hyperkalemia develops in approximately 2–5% of patients, especially those with renal impairment. Rare but serious side effects include angioedema (0.1–0.7%), neutropenia/agranulocytosis, hepatic failure, and pancreatitis. Renal impairment may occur, particularly in volume-depleted patients or those with pre-existing renal disease.

Drug interaction

Lisinopril exhibits significant interactions with potassium-sparing diuretics (spironolactone, triamterene) and potassium supplements, increasing hyperkalemia risk. Concurrent use with NSAIDs may reduce antihypertensive effects and worsen renal function. Dual blockade of the renin-angiotensin system with ARBs or aliskiren increases adverse event risk. Lithium levels may increase due to reduced renal clearance. Diuretics may potentiate first-dose hypotension. Gold injections may rarely cause nitritoid reactions. Insulin and oral hypoglycemics may require dosage adjustment due to potential improved glucose tolerance.

Missed dose

If a dose is missed, it should be taken as soon as possible on the same day. However, if it is near the time for the next scheduled dose, the missed dose should be skipped and the regular dosing schedule resumed. Doubling the dose to compensate for a missed dose is not recommended due to increased risk of hypotension and other adverse effects. Patients should maintain a consistent dosing schedule and consider using pill organizers or reminder systems to improve adherence.

Overdose

Lisinopril overdose may manifest as severe hypotension, which can progress to shock. Bradycardia, electrolyte disturbances (particularly hyperkalemia), and renal failure may occur. Management includes immediate discontinuation of the medication and aggressive supportive care. Primary treatment involves volume expansion with intravenous normal saline to address hypotension. Vasopressors such as dopamine or norepinephrine may be required for refractory hypotension. Bradycardia may necessitate atropine administration. Hemodialysis may be effective in removing lisinopril due to its primarily renal excretion. Serum electrolyte levels and renal function should be monitored closely.

Storage

Store lisinopril tablets at controlled room temperature (20–25°C or 68–77°F) in their original container with the lid tightly closed. Protect from light, moisture, and excessive heat. Keep out of reach of children and pets. Do not store in bathroom cabinets where humidity levels fluctuate. Discard any medication that has expired or shows signs of physical deterioration. Do not flush medications down the toilet or pour into drains unless specifically instructed to do so.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Individual patient responses to lisinopril may vary based on clinical circumstances, comorbidities, and concomitant medications. Healthcare providers should exercise clinical judgment when prescribing, considering individual patient factors and current treatment guidelines. Patients should not initiate, adjust, or discontinue lisinopril without consulting their healthcare provider. The prescribing information provided here may not include all possible uses, directions, precautions, or interactions.

Reviews

Clinical trials consistently demonstrate lisinopril’s efficacy in blood pressure control, with meta-analyses showing mean reductions of 10–15 mmHg systolic and 5–10 mmHg diastolic. In heart failure studies, lisinopril reduced mortality by approximately 16% compared to placebo and decreased hospitalizations for heart failure exacerbations. Post-myocardial infarction trials demonstrated a 27% reduction in mortality at 6 weeks when initiated early. Patient satisfaction surveys indicate generally good tolerability, though the characteristic dry cough leads to discontinuation in approximately 3–5% of patients. Real-world evidence supports its cost-effectiveness and long-term cardiovascular risk reduction benefits.