Medically reviewed on March 14, 2018
What is omeprazole?
Omeprazole is a proton pump inhibitor that decreases the amount of acid produced in the stomach.
Omeprazole is used to treat symptoms of gastroesophageal reflux disease (GERD) and other conditions caused by excess stomach acid. Omeprazole is also used to promote healing of erosive esophagitis (damage to your esophagus caused by stomach acid).
Omeprazole may also be given together with antibiotics to treat gastric ulcer caused by infection with helicobacter pylori (H. pylori).
Over-the-counter (OTC) omeprazole is used to help control heartburn that occurs 2 or more days per week. This medicine not for immediate relief of heartburn symptoms. OTC omeprazole must be taken on a regular basis for 14 days in a row.
Omeprazole may also be used for purposes not listed in this medication guide.
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
Before taking this medicine
Heartburn can mimic early symptoms of a heart attack. Get emergency medical help if you have chest pain that spreads to your jaw or shoulder and you feel anxious or light-headed.
You should not use omeprazole if you are allergic to it, or if:
Ask a doctor or pharmacist if it is safe for you to use omeprazole if you have other medical conditions, especially:
trouble or pain with swallowing;
bloody or black stools, vomit that looks like blood or coffee grounds;
heartburn that has lasted for over 3 months;
frequent chest pain, heartburn with wheezing;
low levels of magnesium in your blood; or
You may be more likely to have a broken bone in your hip, wrist, or spine while taking a proton pump inhibitor. Talk with your doctor about ways to keep your bones healthy.
It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.
Do not use this medicine without a doctor's advice if you are breast-feeding.
Do not give this medicine to a child without medical advice.
How should I take omeprazole?
Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.
Use Prilosec OTC (over-the-counter) exactly as directed on the label, or as prescribed by your doctor.
Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.
Shake the oral suspension (liquid) before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).
If you cannot swallow a capsule whole, open it and sprinkle the medicine into a spoonful of applesauce. Swallow the mixture right away without chewing. Do not save it for later use.
You must dissolve omeprazole powder in a small amount of water. This mixture can either be swallowed or given through a nasogastric (NG) feeding tube using a catheter-tipped syringe.
OTC omeprazole should be taken for only 14 days in a row. Allow at least 4 months to pass before you start a new 14-day course of treatment.
Use this medicine for the full prescribed length of time, even if your symptoms quickly improve.
Taking omeprazole long-term could cause you to develop a vitamin B-12 deficiency. Talk to your doctor about how to manage this condition.
Call your doctor if your symptoms do not improve, or if they get worse.
Some conditions are treated with a combination of omeprazole and antibiotics. Use all medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice.
This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using omeprazole.
Store at room temperature away from moisture and heat.
What happens if I miss a dose?
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking omeprazole?
Diarrhea may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.
Omeprazole side effects
Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using omeprazole and call your doctor at once if you have:
severe stomach pain, diarrhea that is watery or bloody;
a rash or joint pain;
new or unusual pain in your wrist, thigh, hip, or back;
kidney problems--urinating more or less than usual, blood in your urine, swelling, rapid weight gain; or
symptoms of low magnesium--drowsiness, confusion, feeling irritable, fast heartbeats, tremors, twitching, muscle cramps, numbness, tingling, or seizure.
Common side effects may include:
stomach pain, gas;
nausea, vomiting, diarrhea; or
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
What other drugs will affect omeprazole?
Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.
Ask a doctor or pharmacist before using omeprazole with any other medications, especially:
This list is not complete and many other drugs may affect omeprazole. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Copyright 1996-2018 Cerner Multum, Inc. Version: 18.01.
More about omeprazole
- Omeprazole Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Compare Alternatives
- Support Group
- Pricing & Coupons
- 145 Reviews
- Drug class: proton pump inhibitors
- Omeprazole Delayed-Release Capsules and Tablets (OTC)
- Omeprazole Delayed-Release Capsules
- Omeprazole Oral Suspension
- Omeprazole Powder for Oral Suspension
- Omeprazole (Advanced Reading)