Do NOT use Prilosec if:

• you are allergic to any ingredient in Prilosec
• 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 Prilosec. 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 Prilosec. 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 Prilosec's side effects
• Anticoagulants (eg, warfarin), benzodiazepines (eg, diazepam), cilostazol, cyclosporine, digoxin, disulfiram, phenytoin, or tacrolimus because the risk of their side effects may be increased by Prilosec
• Ampicillins, azole antifungals (eg, ketoconazole), clopidogrel, ginkgo biloba, HIV protease inhibitors (eg, atazanavir), or iron because their effectiveness may be decreased by Prilosec.

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

• Prilosec may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Prilosec 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.
• Prilosec may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Prilosec.
• Prilosec should be used with caution in Asian patients; the risk of side effects may be increased in these patients.
• Prilosec should be used with extreme caution in children younger than 2 years old; 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 Prilosec while you are pregnant. Prilosec is found in breast milk. Do not breastfeed while taking Prilosec.

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:

Diarrhea; headache.

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; dark urine; fast or irregular heartbeat; fever, chills, or sore throat; red, swollen, blistered, or peeling skin; swelling of the hands, ankles, or feet; unusual bruising or bleeding; unusual tiredness; vision changes; yellowing of the eyes or skin.

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.