About Zestril

Zestril is the brandname of AstraZeneca Canada & Co. for the substance--Lisinopril, available only on prescription from your physician. Lisinopril is one of a class of medicines known as angiotensin converting enzyme inhibitors. They are usually prescribed to reduce high blood pressure.

When blood pressure is high, the workload of the heart and arteries increases so that over time, these organs may not function as they should. In turn, this could lead to damage of the “vital organs”: brain - heart - kidneys, and result in stroke, heart failure, heart attack, blood vessel disease or kidney disease.

Lisinopril may also be used to treat patients with heart failure. This is a condition where the heart cannot pump adequate amounts of blood to satisfy the needs of the body.


  • This medicine is prescribed for the particular condition that you have. Do not give this medicine to other people, nor use it for any other condition.
  • Do not use outdated medicine.
  • Keep all medicines out of the reach of children.
  • Read the following information carefully. If you need any explanations, or further information, ask your physician or pharmacist.

Before Taking Zestril

This medicine may not be suitable for certain people. So, tell your physician if you think any of the following applies to you:

  • You have previously taken Lisinopril or other medication of the same type (ACE Inhibitors) with the names usually ending with ‘pril' such as enalapril, lisinopril, captopril, and you were allergic or reacted badly to it, particularly if you experienced swelling of the face, lips, tongue, or throat, or had sudden difficulty breathing or swallowing. You should also not take this medicine if you have been diagnosed with hereditary angioedema or idiopathic angioedema (angioedema of unknown cause).
  • You are pregnant or intend to become pregnant. This medicine should not be used during pregnancy, because of possible risks to the fetus.
  • You are breast-feeding or intend to breast-feed.
  • You suffer from low blood pressure (you may notice this as faintness or dizziness, especially when standing).
  • You have any of these conditions:
    • diabetes
    • heart or blood vessel disease
    • liver disease
    • kidney disease

Your physician also needs to know if you are taking any other medication, whether on prescription or otherwise. It is particularly important to inform your physician if you are taking:

  • Diuretics or “water pills”; any other medicines to reduce blood pressure; potassium-containing medicines, potassium supplements, or salt substitutes that contain potassium.
  • Lithium (a drug used to treat a certain kind of depression).
  • Certain pain and arthritis medicines.

You should also inform your physician if you are vomiting or have severe diarrhea.

Proper Use of this Medicine

  • Take this medicine exactly as your physician ordered.
  • The absorption of this medicine is not affected by food; so it can be taken with or without a meal.
  • Try to take your medicine every day at the same time. This way it becomes easy to remember your doses.
  • If you miss a dose of this medicine, take it as soon as possible. However, if no more than 6 hours have elapsed since the missed dose, you may take that day's dose of medication and then go back to your regular dosing schedule. Do not take a double dose.
  • In case of an overdose, contact your doctor immediately so that medical attention may be given promptly. The most likely symptom would be a feeling of lightheadedness or dizziness due to a sudden or excessive drop in blood pressure.
  • Store your tablets between 15 and 30°C, in a tightly closed container, away from heat and direct light, and out of damp places, such as the bathroom or kitchen.

For patients with high blood pressure:

  • If your physician has recommended a particular diet, for instance - less salt - follow the diet carefully. This could help your medicine to better control your blood pressure. Your physician may also recommend weight loss. Do follow these suggestions.
  • This medicine does not cure high blood pressure, but does help control it. So, it is important to continue taking the tablets regularly to keep your blood pressure down. You may have to take high blood pressure medicine for life.
  • Keep your regular appointments with your physician, even if you feel well. High blood pressure may not be easily recognized by you, because you may not “feel any symptoms”; but your physician can measure your pressure very easily, and check how the medicine is controlling it.

For all patients, please note:

  • Do not take any other medicines unless you have discussed the matter with your physician. Certain medications tend to increase your pressure, for example, non-prescription preparations for appetite control, asthma, colds, coughs, hay fever and sinus problems, or may also react badly with Zestril
  • If you have to undergo any dental or other surgery, inform the dentist or the physician in charge that you are taking this medicine.

Side Effects

Along with its intended action, any medication, including Lisinopril, may cause side effects. Most people do not experience any problem when taking this medicine; but if you notice any of the following, medical attention may be needed.

  • Sudden difficulty in breathing or swallowing, swelling of face, eyes, lips, tongue and/or throat, hands or feet. You should be aware that black patients are at increased risk of these types of reactions to ACE inhibitors.
  • Dizziness, lightheadedness or fainting following exercise, and/or when it is hot and you have lost a lot of water by sweating.
  • Flu-like symptoms such as fever, malaise, muscle pain, rash, itching, abdominal pain, nausea, vomiting, diarrhea, jaundice, loss of appetite.
  • Dry cough, sore throat
  • Unusual tiredness and/or weakness
  • Headache

If any fainting occurs, stop taking the medicine. If dizzy, avoid driving or any activity/jobs requiring alertness. Use extra care during exercise or hot weather.

It should be noted that the initial dose may cause a greater fall in blood pressure than will occur following continued treatment. You may notice this as faintness or dizziness and it may help to lie down. If concerned, please consult your physician or pharmacist.