Omeprazole (By mouth)


Omeprazole (oh-MEP-ra-zole)

Treats heartburn, stomach ulcers, and gastroesophageal reflux disease (GERD). Also helps heal a damaged esophagus.

Brand Name(s)

First - Omeprazole, Good Neighbor Pharmacy Omeprazole, Good Sense Omeprazole, Leader Omeprazole, Omeclamox-Pak, Prilosec, Prilosec OTC, Quality Choice Omeprazole Magnesium, Rite Aid Omeprazole, Sunmark Omeprazole, The Medicine Shoppe Omeprazole, TopCare Omeprazole

When This Medicine Should Not Be Used

How to Use This Medicine

Delayed Release Capsule, Packet, Powder for Suspension, Delayed Release Tablet

  • Take your medicine as directed.
  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
  • Follow the instructions on the medicine label if you are using this medicine without a prescription. If you are using the over-the-counter medicine to treat heartburn, do not take it for more than 14 days unless your doctor tells you to. Also, do not use the 14-day treatment more often than every 4 months unless directed by your doctor.
  • Take this medicine at least 1 hour before a meal and for the full time of treatment, even if you begin to feel better after a few days.
  • Capsule or tablet: Swallow whole. Do not crush or chew it. If you cannot swallow the capsule, you may open it and pour the medicine into a small amount of applesauce. Stir this mixture well and swallow it without chewing. Drink a full glass of water to make sure you swallow all of the medicine.
  • Oral suspension:
    • Mix the contents of a 2.5 milligram (mg) packet of powder with 5 milliliters (mL) of water OR mix the contents of a 10 mg packet of powder with 15 mL of water.
    • Use only water. Do not use other liquids or foods.
    • Stir well. Let the mixture thicken for 2 to 3 minutes.
    • Stir and drink within 30 minutes.
    • If any medicine remains after drinking, add more water, stir, and drink immediately.
  • Oral suspension given through a feeding tube:
    • Add 5 mL of water to a catheter-tipped syringe, and then add the contents of a 2.5 mg packet (or use 15 mL of water for the 10 mg packet).
    • Shake the syringe right away. Let the mixture thicken for 2 to 3 minutes.
    • Shake the syringe once more. Give the medicine through the nasogastric or gastric tube into the stomach within 30 minutes.
    • Refill the syringe with an equal amount of water.
    • Shake and flush any remaining contents through the nasogastric or gastric tube.
  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Some medicines can affect how omeprazole works. Tell your doctor if you are also using ampicillin, atazanavir, clarithromycin, clopidogrel, cyclosporine, ketoconazole, nelfinavir, saquinavir, tacrolimus, or voriconazole. Tell your doctor if you are using cilostazol, diazepam, digoxin, disulfiram, phenytoin, rifampin, St John's wort, iron supplements, a blood thinner (such as warfarin), or a diuretic (water pill).

Warnings While Using This Medicine

  • Tell your doctor if you are pregnant or breastfeeding, or if you have liver disease, heart disease, osteoporosis, seizures, or a history of low magnesium levels.
  • Before you use this medicine, tell your doctor if you have had heartburn longer than 3 months, or if you have trouble swallowing food, are vomiting blood, or have blood in your stools.
  • This medicine can cause the following problems:
    • Hypomagnesemia (low magnesium levels)
    • Increased risk of broken bones in the hip, wrist, or spine (more likely if you use high doses or use it for longer than 1 year)
    • Severe diarrhea
  • This medicine can cause diarrhea. Call your doctor if the diarrhea becomes severe, does not stop, or is bloody. Do not take any medicine to stop diarrhea until you have talked to your doctor. Diarrhea can occur 2 months or more after you stop taking this medicine.
  • Call your doctor if your symptoms do not improve or if they get worse.
  • This medicine is sometimes given together with other medicines to treat ulcers. Make sure you understand how to use the combination of medicines.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Blistering, peeling, or red skin rash
  • Fast, slow, or uneven heartbeat
  • Lightheadedness, dizziness, or fainting
  • Seizures, muscle spasms, or tremors
  • Severe diarrhea that does not go away, stomach cramps, and fever
  • Sudden and severe stomach pain, nausea, vomiting, unexplained weight loss

If you notice these less serious side effects, talk with your doctor:

  • Constipation, diarrhea, gas, or stomach pain
  • Fever
  • Headache
  • Stuffy or runny nose, sneezing

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last reviewed on 8/4/2014

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