Omeprazole is used to treat certain stomach and esophagus problems (such as acid reflux, ulcers). It works by decreasing the amount of acid your stomach makes. It relieves symptoms such as heartburn, difficulty swallowing, and persistent cough. This medication helps heal acid damage to the stomach and esophagus, helps prevent ulcers, and may help prevent cancer of the esophagus. Omeprazole belongs to a class of drugs known as proton pump inhibitors (PPIs).
If you are self-treating with this medication, over-the-counter omeprazole products are used to treat frequent heartburn (occurring 2 or more days a week). Since it may take 1 to 4 days to have full effect, these products do not relieve heartburn right away.
For over-the-counter products, carefully read the package instructions to make sure the product is right for you. Check the ingredients on the label even if you have used the product before. The manufacturer may have changed the ingredients. Also, products with similar brand names may contain different ingredients meant for different purposes. Taking the wrong product could harm you.
Headache or abdominal pain may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
If your doctor has directed you to use this product, remember that he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: symptoms of a low magnesium blood level (such as unusually fast/slow/irregular heartbeat, persistent muscle spasms, seizures), signs of lupus (such as rash on nose and cheeks, new or worsening joint pain).
This medication may rarely cause a severe intestinal condition (Clostridium difficile-associated diarrhea) due to a type of bacteria. Do not use anti-diarrhea or opioid medications if you have any of the following symptoms because these products may make them worse. Tell your doctor right away if you develop: persistent diarrhea, abdominal or stomach pain/cramping, fever, blood/mucus in your stool.
Rarely, proton pump inhibitors (such as omeprazole) have caused vitamin B-12 deficiency. The risk is increased if they are taken every day for a long time (3 years or longer). Tell your doctor right away if you develop symptoms of vitamin B-12 deficiency (such as unusual weakness, sore tongue, or numbness/tingling of the hands/feet).
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing, signs of kidney problems (such as change in the amount of urine).
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
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.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, lupus.
Some symptoms may actually be signs of a more serious condition. Get medical help right away if you have: heartburn with lightheadedness/sweating/dizziness, chest/jaw/arm/shoulder pain (especially with shortness of breath, unusual sweating), unexplained weight loss.
In addition, before you self-treat with this medication, get medical help right away if you have any of these signs of a serious condition: trouble/pain swallowing food, bloody vomit, vomit that looks like coffee grounds, bloody/black stools, heartburn for over 3 months, frequent chest pain, frequent wheezing (especially with heartburn), nausea/vomiting, stomach pain.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Proton pump inhibitors (such as omeprazole) may increase your risk for bone fractures, especially with longer use, higher doses, and in older adults. Talk with your doctor or pharmacist about ways to prevent bone loss/fracture, such as by taking calcium (such as calcium citrate) and vitamin D supplements.
Older adults may be more sensitive to the side effects of this drug, especially bone loss and fractures (see above), and Clostridium difficile infection (see Side Effects section).
Children may be more sensitive to the side effects of this drug, especially fever, cough, and infections of the nose/throat/airways.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
This medication passes into breast milk. The effects on a nursing infant are unknown. Consult your doctor before breast-feeding.