Lisinopril is classified as an angiotensin converting enzyme inhibitor and has been available for nearly 3 decades. Lisinopril has some key features that make it different from enalapril and captopril; 1) it has a long half-life 2) it is hydrophilic and 3) it is not broken down by the liver.
Lisinopril is approved by the Food and Drug Administration (FDA) for the management of hypertension in adult and pediatric patients six years and older and as adjunctive therapy in the treatment of heart failure. It is also FDA-approved for the treatment of ST-segment elevation myocardial infarction (STEMI) within 24 hours in hemodynamically stable patients to improve survival.
Lisinopril is a competitive inhibitor of angiotensin-converting enzyme (ACE) and prevents the conversion of angiotensin I to angiotensin II, which is a potent vasoconstrictor. A decrease in angiotensin II subsequently causes a reduction in aldosterone secretion, which causes decrease sodium reabsorption in the collecting duct and decreases potassium excretion that may result in a small increase in serum potassium with lisinopril use. By removing the negative feedback of angiotensin II, lisinopril leads to increased serum renin activity.
The beneficial effects in patients with hypertension derive from the inhibitory effects in the Renin-Angiotensin-Aldosterone System (RAAS), resulting in decreased vasopressor and aldosterone activity even in low-renin patients.
On the other hand, ACE also degrades bradykinin, and it is this mechanism through which ACE inhibitors may predispose to angioedema.
Lisinopril absorption is unchanged by food and is excreted unchanged in the urine. Lisinopril does not have good bioavailability after oral intake - ranging from 10-30%. The time to peak concentration can vary from 6-8 hours. The drug does not bind to albumin or other proteins and its distribution in patients with heart failure is poor.
In general, it is recommended that the administration of lisinopril should be adjusted for patients in whom the glomerular filtration rate (GFR) is less than or equal to 30 mL/min.
In adults, the usual dosage ranges from 2.5 to 40 mg per day depending on the indication. For adolescents and children greater than or equal to 6 years, the initial dose is 0.07 to 0.1 mg/kg once daily with a maximum initial dose of 5 mg/day and increments of 1- to 2-week intervals. The maximum pondered dose is 0.6 mg/kg/day or 40 mg/day.
For heart failure, the 2013 ACCF/AHA Guideline for the Management of Heart Failure (HF) recommends ACE inhibitors in all patients with HF with reduced ejection fraction (HFreEF) to reduce morbidity and mortality with a level A of evidence. The initial dose recommended is 2.5 mg per day with a maximum daily dose of 40 mg. An inclination to higher doses is influenced by the findings of the SOLVD trial where people in the high-dose group had an overall 8% decrease of death compared to those in the low-dose group.
Lisinopril is also strongly recommended by the 2013 ACCF/AHA Guideline (Level of Evidence, A) within the first 24 hours to all patients with STEMI with the anterior location, HF, or those with reduced Ejection Fraction (EF) less than or equal to 40%, unless contraindicated. Recommended starting dose for this indication is 2.5 to 5 mg per day with a 10 mg daily titration up to maximal dose tolerated in hemodynamically stable patients.
According to the recent 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults, among patients in whom pharmacological therapy is indicated, ACE inhibitors are among the recommended first-line agents for the management of hypertension with a lisinopril starting dose of 10 mg up to 40 mg daily.
The American Diabetes Association (ADA) recommends the use of ACE inhibitors as one of the first-line agents for hypertension in patients with diabetes and urinary albumin–to–creatinine ratio greater than or equal to 300 mg/g creatinine or 30 to 299 mg/g creatinine.
The primary adverse effects of ACE inhibitors include hyperkalemia, dry cough, angioedema, hypotension, dizziness, and renal insufficiency. These effects may be more common in patients with renal, autoimmune, or collagen vascular diseases.
The AHA/ACCF recommends careful use in patients with cardiomyopathy with outflow obstruction, as they may lead to exacerbation of symptoms.
Historically, ACE inhibitors have been associated with an increase in morbidity and mortality in patients with aortic stenosis, however, recent randomized and placebo-controlled trials suggest that ACE inhibitors might be safe and might even provide some benefits in certain patients.
It is contraindicated in patients with hyperkalemia, a history of angioedema, renal failure with prior lisinopril use, bilateral renal artery stenosis, concomitant use with aliskiren in patients with diabetes mellitus, and during coadministration with a neprilysin inhibitor or within 36 hours of taking one.
It is Pregnancy Category Class D due to its teratogenic effects (e.g., decreased fetal renal function, oligohydramnios, lung hypoplasia, skeletal malformations, death in the fetus/neonate, etc.), thus its use is contraindicated in pregnant women and/or fertile women without proper contraception. Manufacturers recommend against the use of lisinopril in breastfeeding woman because the amount secreted in breast milk and its effects in the breastfed infant is unknown.
No contraindications are known for patients with hepatic impairment.
First-dose hypotension is an uncommon adverse effect of ACE inhibitors that clinicians should bear in mind when prescribing lisinopril, and thus a low starting dose is recommended to reduce the risk of this phenomenon.
Monitor serum potassium, blood pressure, and blood urea nitrogen/serum creatinine in patients taking lisinopril after 2 to 3 weeks of initiation.
Caution must be exercised when prescribing lisinopril in patients with high potassium diets or among people taking other agents that might exacerbate hypotension and hyperkalemia, such as antihypertensive agents, or aldosterone antagonists,.
Although cholestatic jaundice is a rare reaction associated to captopril use, another ACE inhibitor drug, monitoring of liver function during lisinopril use may be appropriate with timely discontinuation if the elevation of liver enzymes has been detected.
Since lisinopril metabolism depends on renal excretion, overdose management consists of general supportive care, including gastric emptying strategies when appropriate, intravenous fluids, vasopressors, and hemodialysis. Maintenance of optimal blood pressure with fluids is critical in patients who are hypotensive. Some reports suggest the use of Angiotensin II administration as an alternative supportive treatment for the treatment of ACE inhibitors overdose.
There is no antidote available for lisinopril.