treat heartburn caused by gastroesophageal reflux disease (GERD), and to heal erosive esophagitis (damage to the esophagus from stomach acid)

Headache or abdominal pain may occur.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, lupus or hypersensitivity to the drug.

Before taking omeprazole, tell your doctor or pharmacist if you are allergic to it; or to similar drugs (such as esomeprazole, lansoprazole, pantoprazole); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Please consult your doctor when taking this medicine if you are pregnant.

Drugs that may interact with this drug are Cilostazol, clopidogrel, methotrexate(especially high-dose treatment), rifampin, St John's wort.