Do NOT use Prevacid:

• you are allergic to any ingredient in Prevacid
• you are taking an HIV protease inhibitor (eg, atazanavir).

Contact your doctor right away if any of these apply to you.

Some medical conditions may interact with Prevacid. 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 have liver problems or stomach or bowel cancer.

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

• Clarithromycin or voriconazole because they may increase the risk of Prevacid's side effects
• Anticoagulants (eg, warfarin) or digoxin because the risk of their side effects may be increased by Prevacid
• Azole antifungals (eg, ketoconazole), clopidogrel, HIV protease inhibitors (eg, atazanavir), iron, or theophylline because their effectiveness may be decreased by Prevacid.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Prevacid 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:

• Prevacid may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Prevacid with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Contact your doctor if you have any symptoms of a bleeding ulcer, such as black, tarry stools or vomit that looks like coffee grounds; or if you experience throat pain, chest pain, severe stomach pain, or trouble swallowing.
• Prevacid may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Prevacid.
• Prevacid should be used with caution in Asian patients; the risk of side effects may be increased in these patients.
• Prevacid should be used with extreme caution in children younger 1 year; safety and effectiveness in these children have not been confirmed.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Prevacid while you are pregnant. It is not known if Prevacid is found in breast milk. Do not breastfeed while taking Prevacid.

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:

Constipation; diarrhea; headache; nausea; stomach pain.

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 mouth, face, lips, or tongue; unusual hoarseness); chest pain; fast or irregular heartbeat; fever, chills, or sore throat; red, swollen, blistered, or peeling skin; seizure; unusual bruising or bleeding; unusual tiredness; vision changes.

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.