Generic name: Lisinopril (lyse IN oh pril)

Brand names: Prinivil, Zestril

Zestril (lisinopril) is an ACE inhibitor. ACE stands for angiotensin-converting enzyme. Zestril is used to treat high blood pressure (hypertension), congestive heart failure, and to improve survival after a heart attack.

ACE inhibitors work by relaxing blood vessels and reducing the workload of the heart. This can help to lower blood pressure and reduce strain on the heart. Zestril can be used alone or in combination with other medications.

If you have high blood pressure, Zestril can help to lower it. This can reduce your risk of having a heart attack or stroke. If you have congestive heart failure, Zestril can help to improve your symptoms and quality of life. If you have had a heart attack, Zestril can help to improve your survival rate.

Zestril is a prescription medication. It is available as an oral tablet in strengths of 5 mg, 10 mg, and 20 mg. The usual starting dose is 10 mg once daily. Your doctor may increase or decrease your dose based on your individual needs.

You should take Zestril exactly as prescribed by your doctor. Do not take it in larger or smaller amounts or for longer or shorter than recommended. Follow the directions on your prescription label.

Zestril can be taken with or without food. Take the medicine at the same time each day.


The pharmacokinetics of lisinopril are linear and dose-proportional over the therapeutic range. Lisinopril is rapidly absorbed from the gastrointestinal tract after oral administration, with peak plasma concentrations achieved within about 1 hour. The bioavailability of lisinopril is about 25%, and absorption is not affected by food.

Lisinopril is extensively metabolized in the liver to two major metabolites: a carboxylic acid derivative and an acylglucuronide conjugate of the parent compound. Both metabolites are pharmacologically active, with the carboxylic acid derivative having a longer half-life than lisinopril (approximately 12 hours vs. 2 hours). The total clearance of lisinopril is about 34 mL/min in patients with normal renal function.

Lisinopril is eliminated primarily by renal excretion, with about 40% of the dose recovered unchanged in the urine. Renal clearance of lisinopril (approximately 300 mL/min) exceeds the glomerular filtration rate, indicating that tubular secretion contributes to its elimination. Urinary recovery of lisinopril is about 10% of the oral dose.

In patients with renal impairment, the half-life and total clearance of lisinopril are increased. Plasma concentrations of lisinopril in patients with severe renal impairment (CrCl <10 mL/min) are approximately doubled compared to those in healthy volunteers.

Drug interactions

Lisinopril can interact with other medications, herbs, or vitamins you might be taking. Be sure to talk to your healthcare provider about all the medications, herbs, and vitamins you are taking before starting lisinopril.

Some of the drugs that can interact with lisinopril include:

ACE inhibitors, such as benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril (Monopril), moexipril (Univasc), perindopril (Aceon), quinapril (Accupril), and ramipril (Altace)

Angiotensin receptor blockers, such as candesartan (Atacand), eprosartan (Teveten), irbesartan (Avapro), losartan (Cozaar), olmesartan (Benicar), telmisartan (Micardis), and valsartan (Diovan)

Non-steroidal anti-inflammatory drugs (NSAIDs), such as celecoxib (Celebrex), diclofenac (Voltaren, Cataflam), ibuprofen (Advil, Motrin), indomethacin (Indocin), and naproxen (Aleve, Naprosyn)

Potassium-sparing diuretics, such as amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium)

Side Effects

The most common side effects of lisinopril are dizziness, headache, coughing, and fatigue. Other potential side effects include kidney problems, skin rash, and allergic reactions. If you experience any serious side effects, contact your doctor or seek medical attention immediately.

Lisinopril may cause a small drop in blood pressure when you stand up from a sitting or lying position. This is known as postural hypotension and is most likely to occur if you have been taking lisinopril for a long time. If you experience this side effect, be sure to rise slowly from a sitting or lying position to avoid dizziness or lightheadedness.

Dosage and Administration

The recommended starting dose of lisinopril is 10 mg once daily. The usual maintenance dose is 20-40 mg once daily. Lisinopril can be given alone or in combination with other medications.

Lisinopril should be taken at the same time each day. It can be taken with or without food. If you miss a dose, take it as soon as possible and continue with your regular dosing schedule. Do not take two doses at once.

If you miss a dose of Zestril, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take two doses at once.


If you take too much lisinopril, you may experience low blood pressure (hypotension), dizziness, or fainting. If you think you have taken too much of this medicine, contact your local poison control center or emergency room immediately.


Store Zestril at room temperature away from moisture and heat.