Zestril (Lisinopril) - Oral


Zestril (lisinopril) should be stopped as soon as possible if you become pregnant during treatment. If it is used during pregnancy, this medication can cause serious—possibly fatal—harm to a fetus. Contact your healthcare provider immediately if you are taking Zestril and think you could be pregnant.

What Is Zestril?

Zestril (lisinopril) is an angiotensin-converting enzyme (ACE) inhibitor drug that is used to control blood pressure and treat heart failure. Zestril can also be given within 24 hours of a heart attack to improve survival in people with stable blood flow.

The renin-angiotensin system's main function in the body is to regulate blood pressure. One of its core components is a hormone called angiotensin II, which causes the narrowing of blood vessels and fluid retention that results in high blood pressure.

Zestril blocks the formation of angiotensin II. This allows the blood vessels to relax and reduces fluid buildup, which in turn lowers blood pressure.

Zestril, the brand name for lisinopril, is available as a long-acting oral tablet. Lisinopril is also sold under another brand name, Qbrelis, as an oral solution (liquid). Healthcare providers may also prescribe generic lisinopril.

Drug Facts

Generic Name: Lisinopril

Brand Name(s): Zestril, Qbrelis

Drug Availability: Prescription

Administration Route: Oral

Therapeutic Classification: Antihypertensive

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Lisinopril

Dosage Form(s): Tablet, solution

What Is Zestril Used For?

Zestril is approved by the Food and Drug Administration (FDA) to:

  • Treat high blood pressure (hypertension) in adults and children aged 6 years and older
  • Reduce the symptoms of systolic heart failure (also known as heart failure with reduced ejection fraction)
  • Improve survival in people with stable blood flow who have had a heart attack within the last 24 hours

Zestril may be used on its own (monotherapy) or in combination with other antihypertensive drugs. Recent blood pressure guidelines from national health agencies—including the American College of Cardiology and the American Heart Association—recommend using ACE inhibitors as the initial drug therapy for managing high blood pressure.

Whether you receive Zestril as initial therapy for hypertension depends on if you have a history of complicated or uncontrolled high blood pressure with the use of diuretics.

How to Take Zestril

Take Zestril exactly as prescribed. Try to take it at around the same time daily. It is best to take blood pressure medication at night one hour before going to bed, so you’re less likely to have side effects.

You can take the tablets with water or milk. Zestril may be taken with or without food. Food will not affect the dose of this medication. However, it's advised to avoid consuming alcohol while taking this medication.

Most medications are OK to take with Zestril, except for drugs that should be taken by themselves early in the morning (for example, thyroid medications).

Develop a strategy for remembering to take your doses every day.

Your dose of Zestril may depend on a number of factors, such as your current blood pressure, your symptoms, your kidney function, and whether you are taking diuretics. Ask your healthcare provider for instructions on how to take your medication.


Store Zestril oral tablets in a dry, cool setting at temperatures between 68 F and 77 F. Exposure to heat, air, light, or moisture can damage the medication. If the medication is not stored properly, the pills could become less potent or effective or may "go bad" before the expiration date.

People often store their medications in a bathroom cabinet, but heat and moisture from the shower can ruin medications. You should also avoid storing your medication in cabinets above the stove. The heat from the stove could damage the drug, making it less effective.

Do not store Zestril in a hot or frozen environment such as your car, outdoors, or in the refrigerator. Keep your medicines in a box, shelf, or closet away from these areas. Make sure your Zestril is kept in its tightly closed original container and stored out of reach of children and pets.

Do not take expired tablets. Return any unused pills to your pharmacist.

Off-Label Uses

Lisinopril has a history of many “off-label” uses, which means the drug is prescribed for a purpose not specified by the FDA but deemed medically appropriate.

Off-label uses of lisinopril include:

  • Kidney disease with loss of protein in the urine (proteinuric kidney disease)
  • Irregular heart rhythm (atrial fibrillation)
  • Heart disease that affects the heart muscle (cardiomyopathy) in people with Duchenne muscular dystrophy
  • A diabetes complication affecting the eyes called diabetic retinopathy
  • Increase in collagen in the heart tissue (myocardial fibrosis)
  • A vision-related disorder that affects the central retina or macula (inflammatory cystoid macular edema)
  • Thickening of the heart's left pumping chamber (left ventricular hypertrophy)
  • Migraine 
  • A type of heart valve disease called mitral valve regurgitation
  • Low sperm count (oligospermia) and infertility 
  • Prevention of diabetes 
  • Prevention of pneumonia

How Long Does It Take for Zestril to Work?

Zestril can start to take effect within six hours of taking your first dose. However, studies have shown that lisinopril has a slightly less antihypertensive effect in Black patients compared to patients of other racial/ethnic backgrounds. Therefore, Black patients may need to be prescribed additional medications to achieve the desired blood-pressure-lowering effects.

What Are the Side Effects of Zestril?

This is not a complete list of side effects of Zestril, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your provider. You may also report side effects to the FDA at fda.gov/medwatch or 1-800-FDA-1088.

Common Side Effects

Zestril has been on the market since 1988. As an older medication, its side effects are better understood than newer medications.

Below are the potential side effects of Zestril based on the condition it is being used to treat.

Side effects when using Zestril for the treatment of hypertension may include:

  • Dizziness
  • Dry cough (let your healthcare provider know if you experience this side effect)
  • Headaches

When used for heart failure, common side effects are:

  • Low blood pressure (hypotension)
  • Chest pain
  • Dizziness
  • Increased creatinine
  • High potassium levels (hyperkalemia)
  • Fainting (syncope)

If being treated for a heart attack, Zestril may cause the following:

  • Hypotension
  • Headaches
  • Tired
  • Syncope
  • Constipation, flatulence, or diarrhea
  • Gout
  • Skin rashes, hives, itching, or photosensitivity
  • Sexual dysfunction (impotence)

Severe Side Effects

Contact your healthcare provider immediately if you have serious side effects while using Zestril. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

Emergency care may be needed if any of the following severe side effects occur:

  • Swelling of the face, throat, tongue, or lips
  • Rash or hives
  • Swelling of the hands, feet, ankles, or lower legs
  • Difficulty breathing or swallowing
  • Irregular heartbeat
  • Dizziness or fainting
  • Difficulty urinating

These serious side effects could be associated with angioedema, which is unusual swelling of the lips, face, or extremities.

Long-Term Side Effects

Zestril is generally safe to use, even long-term. One study showed that people with heart failure taking lisinopril for four years had minimal side effects. The side effects reported were similar to the common side effects listed above.

Report Side Effects

Zestril may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (1-800-332-1088).

Dosage: How Much Zestril Should I Take?

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The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage forms (solution or tablets):
    • For high blood pressure:
      • Adults—At first, 10 milligrams (mg) once a day. Your doctor may increase your dose as needed. However, the dose is usually not more than 40 mg per day.
      • Children 6 years of age and older—Dose is based on body weight and must be determined by your doctor. The starting dose is usually 0.07 mg per kilogram (kg) of body weight per day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 0.61 mg per kg of body weight or 40 mg per day.
      • Children younger than 6 years of age—Use is not recommended.
    • For heart failure:
      • Adults—At first, 5 milligrams (mg) once a day. Your doctor may increase your dose as needed. However, the dose is usually not more than 40 mg per day.
      • Children—Use and dose must be determined by your doctor.
    • For immediate treatment after a heart attack:
      • Adults—At first, 5 milligrams (mg), followed by 5 mg after 24 hours, followed by 10 mg after 48 hours, and then 10 mg once a day.
      • Children—Use and dose must be determined by your doctor.


The dosing for this medication is dependent on your disease state, age, current medication regimen, blood pressure, and kidney function.

If you are 65 or older with high blood pressure, your healthcare provider may prescribe the lowest dose possible and then increase it, depending on your response to treatment.

Zestril is approved for use in children 6 and older; however, research is limited on its safety or efficacy in children younger than 6. Talk to your child's healthcare provider in regard to their treatment plan. Children and adolescents may be dosed differently than adults at first.

Missed Dose

If you miss a dose, take the missed dose as soon as you remember. If one day has passed, simply skip the missed dose and go back to your normal dose time. Do not take two doses at once or an extra dose earlier or later in the day. The possible side effects of a missed dose are not as severe as double dosing and may include higher-than-normal blood pressure.

Overdose: What Happens If You Take Too Much Zestril?

The most common side effect of taking too much Zestril is decreased blood pressure.

Low blood pressure can cause fatigue, lightheadedness, dizziness, nausea, and even a loss of consciousness. To get treated for low blood pressure caused by a Zestril overdose, immediately go to an emergency room.

An overdose of Zestril should not be self-managed at home. A standard treatment for low blood pressure is a saline solution.

Once at the emergency room, there are different methods of removing Zestril from the body. If you get to an emergency room within one hour of an overdose, you may receive activated charcoal to prevent more Zestril from being absorbed. If the Zestril has already been mostly absorbed, you may need to have a dialysis procedure that will remove it from your blood.

What Happens If I Overdose on Zestril?

If you think you or someone else may have overdosed on Zestril, call a healthcare provider or the Poison Control Center (1-800-222-1222).

If someone collapses or isn't breathing after taking Zestril, call 911 immediately.


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It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.

This medicine may cause serious types of allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, mouth, or throat while you are using this medicine.

Call your doctor right away if you have severe stomach pain (with or without nausea or vomiting). This could be a symptom of intestinal angioedema.

Dizziness, lightheadedness, or fainting may also occur, especially when you get up from a lying or sitting position or if you have been taking a diuretic (water pill). Make sure you know how you react to the medicine before you drive, use machines, or do other things that could be dangerous if you are dizzy or not alert. If you feel dizzy, lie down so you do not faint. Then sit for a few moments before standing to prevent the dizziness from returning.

Check with your doctor right away if you become sick while taking this medicine, especially with severe or continuing nausea, vomiting, or diarrhea. These conditions may cause you to lose too much water or salt and may lead to low blood pressure. You can also lose water by sweating, so drink plenty of water during exercise or in hot weather.

Check with your doctor if you have a fever, chills, or sore throat. These could be symptoms of an infection resulting from low white blood cells.

Hyperkalemia (high potassium in the blood) may occur while you are using this medicine. Check with your doctor right away if you have the following symptoms: abdominal or stomach pain, confusion, difficulty with breathing, irregular heartbeat, nausea or vomiting, nervousness, numbness or tingling in the hands, feet, or lips, shortness of breath, or weakness or heaviness of the legs. Do not use supplements or salt substitutes containing potassium without first checking with your doctor.

Check with your doctor right away if you have upper stomach pain, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

This medicine may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests, or if you have any questions, check with your doctor.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine several days before having surgery.

This medicine may be less effective in black patients. Black patients also have an increased risk of angioedema (swelling of the hands, arms, face, mouth, or throat).

Do not take other medicines unless they have been discussed with your doctor. This includes over-the-counter (nonprescription) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.

What Are Reasons I Shouldn’t Take Zestril?

Do not take Zestril if any of the following apply to you:

  • Have an allergy or have had an allergic reaction to Zestril or similar medications in the past
  • Develop an abnormal rash while taking Zestril (i.e., angioedema) or have a personal or family history of angioedema
  • Have heart failure and recently taken Entresto (sacubitril and valsartan) (in this case, wait at least 36 hours before taking Zestril)
  • Have diabetes and take a medication called aliskiren
  • Have a condition known as bilateral renal artery stenosis
  • Are pregnant or may become pregnant

What Other Medications Interact With Zestril?

Ask your healthcare provider before starting any new products, including over-the-counter (OTC) medications, prescription drugs, vitamins, and herbal supplements. Having this information is important to prevent drug interactions.

A few drug interactions can occur with Zestril. The interactions can cause various side effects or affect how the medications work.


The goal of taking aspirin is to reduce aches and pains or prevent the risk of blood clots. When taken with Zestril, Aspirin may enhance kidney toxicity and decrease the therapeutic effects of Zestril.

However, this interaction may not be observed in every instance. Studies evaluating the effects of taking aspirin and lisinopril at the same time have produced conflicting results about a potential interaction. Therefore, close monitoring is recommended. It is best to talk with your provider to find out if the benefits of taking aspirin outweigh the potential risks.

Food and Drugs that Increase Potassium

One common side effect of Zestril is an increase in potassium levels in the blood. Therefore, you should limit how many foods high in potassium you eat to prevent these effects. Some examples of foods high in potassium are leafy vegetables, bananas, and some types of salt.

Additionally, there are other medications that can increase your potassium levels. Aldactone (spironolactone) is a medication used to treat heart failure and high blood pressure. Taking spironolactone with Zestril can increase the risk of excessive potassium levels. Talk with your provider about having your potassium levels monitored periodically.

Drugs in the Same Class

You should avoid taking drugs that are in the same class as Zestril, such as Altace (ramipril) or Vasotec (enalapril). These are duplicate therapies and can exacerbate side effects, so you should not take them together.

There are also other blood pressure medications that belong to different drug classes, such as angiotensin II receptor blockers (ARBs). Two common ARBs are Diovan (valsartan) and Cozaar (losartan). Although the mechanisms of the two drugs are different from Zestril, taking them at the same time is not recommended.

What Medications Are Similar?

Like Zestril, other ACE inhibitors may be used to treat blood pressure. Most ACE inhibitors' names will end "-pril," but not all drugs with this suffix are part of the ACE inhibitor class.

Examples of ACE inhibitors include:

What makes Zestril unique compared with the other ACE inhibitors? Studies looking at Zestril's active ingredient (lisinopril) compared with other ACE inhibitors found that:

  • Lisinopril had the worst reduction in blood pressure compared with other ACE inhibitors. Other ACE inhibitors—like captopril and enalapril—had better decreases.
  • Lisinopril can moderately decrease kidney function. Enalapril has a greater effect on reducing kidney function, whereas captopril has the least effect. 
  • Lisinopril performed better in people with digestive tract issues in comparison with enalapril and captopril. 
  • Out of four total ACE inhibitors, lisinopril was the least effective in treating heart failure and was associated with a greater chance of all-cause death. The other ACE inhibitors that were used (enalapril, captopril, and ramipril) all had lower chances of all-cause death.

The drugs mentioned here are commonly prescribed as an alternative to Zestril. It is NOT a list of drugs recommended to take with Zestril. You should not take these drugs together. Talk to a pharmacist or your provider if you have questions about your medications.

Frequently Asked Questions

  • What is Zestril used for?

    Zestril can be used to lower high blood pressure in adults and children aged 6 years and older, treat heart failure, and improve survival after heart attacks.

  • How does Zestril work?

    Zestril blocks the formation of a core component of the renin-angiotensin system, called angiotensin II. The renin-angiotensin system plays an important role in regulating blood pressure in the body. Blocking angiotensin II in this system relaxes the blood vessels, which reduces blood pressure.

  • What are the side effects of Zestril?

    Common side effects of Zestril are cough, dizziness, headaches, low blood pressure, and increased potassium levels. Severe side effects include angioedema, rash or hives, difficulty breathing or swallowing, irregular heartbeat, dizziness or fainting, and difficulty urinating. Talk to your healthcare provider if you have side effects that are bothersome or worsening.

  • What should I do if I miss a dose?

    If you miss a dose of Zestril, take it as soon as you remember. If one day has passed, skip the missed dose and return to your regular dose time. You should not take two doses at once to make up for a missed dose. Take only one dose.

  • How do I safely stop taking Zestril?

    Zestril should only be stopped if your prescribing healthcare provider says it is OK. Never stop taking this medication on your own.

How Can I Stay Healthy While Taking Zestril?

Staying healthy while taking Zestril means taking your medication daily to get the maximum benefits.

High blood pressure is known to be a silent killer. High blood pressure may not cause daily symptoms that would warn you of increases that could lead to an eventual stroke or heart attack.

When life gets busy, it’s easy to forget to take your medication, but a routine can help you stay on schedule.

The following tips can help ensure you don't miss a dose:

  • Keep a pillbox beside your bed with an alarm to help you remember to take it every morning when you wake up
  • Use electronic pill reminders on your phone
  • Get in the habit of taking your pill with your main meal of the day

Buying a blood pressure monitor can help you do daily measuring of your blood pressure at home. Maintaining a balanced diet, exercising regularly, and staying hydrated will also help you combat high blood pressure.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration. Zestril label.

  2. Food and Drug Administration. Qbrelis label.

  3. Whelton PK, Carey RM, Aronow WS, et al. 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. a report of the America College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2018;71(19)e127-e248.

  4. Sadat-Ebrahimi S-R, Parnianfard N, Vahed N, et al. An evidence-based systematic review of the off-label uses of lisinopril. Br J. Clin Pharmacol. 2018;84(11):2502-2521. doi:10.1111/bcp.13705

  5. Moyses C, Higgins TJC. Safety of long-term use of lisinopril for congestive heart failure. J Am Coll Cardiol. 1992;70(10):91-97. doi:10.1016/0002-9149(92)91364-a

  6. Toxicology AA of C, Centres EA of P, Toxicologists C. Position paper: single-dose activated charcoal. LCLT. 2005;43(2):61-87. doi:10.1081/clt-200051867

  7. Prescribers' Digital Reference. Lisinopril - drug summary.

  8. Mahé I, Meune C, Diemer M, Caulin C, Bergmann JF. Interaction between aspirin and ACE inhibitors in patients with heart failure. Drug Saf. 2001;24(3):167-182. doi:10.2165/00002018-200124030-00002

  9. Abbas S, Ihle P, Harder S, Schubert I. Risk of hyperkalemia and combined use of spironolactone and long-term ACE inhibitor/angiotensin receptor blocker therapy in heart failure using real-life data: a population- and insurance-based cohort: HYPERKALEMIA AND SPIRONOLACTONE/ACE INHIBITOR. Pharmacoepidemiol Drug Saf. 2015;24(4):406-413. doi:10.1002/pds.3748

  10. Misra S, Stevermer JJ. ACE inhibitors and ARBs: one or the other--not both--for high-risk patients. J Fam Pract. 2009;58(1):24-27.

  11. Sun W, Zhang H, Guo J, et al. Comparison of the efficacy and safety of different ace inhibitors in patients with chronic heart failure: a prisma-compliant network meta-analysis. Medicine. 2016;95(6):e2554. doi:10.1097/MD.0000000000002554