Do NOT use Zestril if:

• you are allergic to any ingredient in Zestril
• you have a history of angioedema (swelling of the hands, face, lips, eyes, throat, or tongue; difficulty swallowing or breathing; or hoarseness), including angioedema caused by treatment with an ACE inhibitor
• you are in your second or third trimester of pregnancy
• the patient is a child with severe kidney problems.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Zestril. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you are able to become pregnant
• if you have a history of heart problems (eg, heart failure, aortic stenosis), blood vessel problems, blood flow problems, bone marrow problems, kidney problems, or diabetes
• if you have a history of stroke, recent heart attack, or kidney transplant
• if you have an autoimmune disease (eg, rheumatoid arthritis, lupus, scleroderma)
• if you are dehydrated or have low blood volume
• if you have high blood potassium levels, low blood sodium levels, or are on a low salt (sodium) diet
• if you are on dialysis or are scheduled to have major surgery.

Some medicines may interact with Zestril. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Diuretics (eg, furosemide, hydrochlorothiazide) because the risk of low blood pressure may be increased
• Aldosterone blockers (eg, eplerenone), potassium-sparing diuretics (eg, spironolactone, triamterene), or potassium supplements because the risk of high blood potassium levels may be increased
• Insulin, sulfonylureas (eg, glipizide), or other oral diabetes medicines (eg, metformin) because the risk of low blood sugar may be increased
• Gold-containing medicines (eg, auranofin) because flushing, nausea, vomiting, and low blood pressure may occur
• Nonsteroidal anti-inflammatory drugs (NSAIDs) (eg, ibuprofen, indomethacin, celecoxib) or salicylates (eg, aspirin) because they may decrease Zestril's effectiveness
• Lithium or thiopurines (eg, azathioprine) because the risk of their side effects may be increased by Zestril.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Zestril may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Zestril may cause dizziness, lightheadedness, or fainting. These effects may be worse if you take it with alcohol or certain medicines. Use Zestril with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Zestril may cause a serious side effect called angioedema. Contact your doctor at once if you develop swelling of the hands, face, lips, eyes, throat, or tongue; difficulty swallowing or breathing; or hoarseness.
• Zestril may not work as well in black patients. They may also be at greater risk of side effects. Contact your doctor if your symptoms do not improve or if they become worse.
• Dehydration, excessive sweating, vomiting, or diarrhea may increase the risk of low blood pressure. Contact your health care provider at once if any of these occur.
• Rarely, Zestril may lower the ability of your body to fight infection. This risk may be greater if you have certain other health problems (eg, kidney problems, collagen vascular disease). Avoid contact with people who have colds or infections. Tell your doctor if you notice signs of infection like fever, sore throat, rash, or chills.
• Check with your doctor before you use a salt substitute or a product that has potassium in it.
• Tell your doctor or dentist that you take Zestril before you receive any medical or dental care, emergency care, or surgery.
• Patients who take medicine for high blood pressure often feel tired or run down for a few weeks after starting treatment. Be sure to take your medicine even if you may not feel "normal." Tell your doctor if you develop any new symptoms.
• If you have high blood pressure, do not use nonprescription products that contain stimulants. These products may include diet pills or cold medicines. Contact your doctor if you have any questions or concerns.
• Diabetes patients- Zestril may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
• Lab tests, including blood pressure, blood electrolyte levels, heart function, or kidney or liver function, may be performed while you use Zestril. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Use Zestril with caution in the elderly; they may be more sensitive to its effects.
• Zestril should not be used in children younger 6 years; safety and effectiveness in these children have not been confirmed.
• Pregnancy and breast-feeding: Zestril may cause birth defects or fetal death if you take it while you are pregnant. If you think you may be pregnant, contact your doctor right away. It is not known if Zestril is found in breast milk. Do not breastfeed while taking Zestril.

All medicines may cause side effects, but many people have no, or minor, side effects.

Check with your doctor if any of these most common side effects persist or become bothersome:

Cough; diarrhea; dizziness; headache; tiredness.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the hands, eyes, mouth, face, lips, or tongue; hoarseness); chest pain; dark urine; decreased urination; difficulty swallowing; infection (eg, fever, chills, persistent sore throat); irregular or slow heartbeat; stomach pain (with or without nausea or vomiting); symptoms of low blood pressure (eg, fainting, severe dizziness, lightheadedness); yellowing of the skin or eyes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.