Omeprazole comes as an extended-release (long-acting) capsule. It usually is taken once a day, before a meal. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take omeprazole exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Do not open, crush, break, or chew the capsules; swallow them whole

Although side effects from omeprazole are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

headache
diarrhea
constipation
upset stomach
vomiting
stomach pain
cough
cold symptoms
dizziness
mild rash
If you experience the following symptom, call your doctor immediately:

severe skin rash with swelling and peeling

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to omeprazole.

Do not let anyone else take your medicine. Ask your pharmacist any questions you have about refilling your prescription

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Omeprazole is used to prevent ulcers and to treat other conditions where the stomach produces too much acid. It decreases the amount of acid made in the stomach.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication

Before taking omeprazole,

tell your doctor and pharmacist if you are allergic to omeprazole or any other drugs.
tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially amoxicillin (Amoxil, Trimox), ampicillin (Omnipen, Polycillin, Totacillin), cisapride (Propulsid), clarithromycin (Biaxin), diazepam (Valium), erythromycin (E.E.S., E-Mycin, Erythrocin), iron, ketoconazole (Nizoral), phenytoin (Dilantin), pimozide (Orap), terfenadine (Seldane), warfarin (Coumadin), and vitamins.
tell your doctor if you have or have ever had liver disease.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking omeprazole, call your doctor.
tell your doctor if you use tobacco products. Cigarette smoking may decrease the effectiveness of this drug