What is Omeprazole: Uses, Warnings & Interactions

Updated Feb 21, 2024  •  Published Dec 30, 2020

Omeprazole overview

BRAND NAMES:

  • Prilosec, Prilosec OTC

Generic Names:

  • Omeprazole, omeprazole magnesium

Uses:

  • Treats heartburn (OTC omeprazole), symptomatic gastroesophageal reflux disease (GERD) (Rx), esophagus damage due to GERD (Rx), stomach and duodenal ulcers (Rx), H. pylori infection (Rx), and conditions that cause your stomach to make too much acid (Rx).

Therapeutic Classes:

  • Proton pump inhibitor, gastric acid secretion inhibitor

Forms:

  • Delayed-release tablet, delayed-release capsule, delayed-release orally disintegrating tablet, delayed-release granules for oral suspension

How it’s taken:

  • By mouth

What is Omeprazole used for?

Over-the-counter omeprazole treats frequent heartburn, defined as heartburn that occurs two or more times a week. The FDA has approved prescription omeprazole to treat symptomatic gastroesophageal reflux disease (GERD), esophagus damage due to GERD, active ulcers in the stomach or duodenum, and part of triple therapy to eliminate Helicobacter pylori infections, a cause of stomach and duodenal ulcers. It’s also prescribed as a long-term treatment for conditions in which the stomach produces too much acid.

What form(s) does Omeprazole come in

  • Delayed-release tablet

    • 20 mg

  • Delayed-release capsule

    • 10 mg

    • 20 mg

    • 40 mg

  • Delayed-release orally disintegrating tablet

    • 20 mg

  • Granules for oral suspension (liquid)

    • 2.5 mg

    • 10 mg

What are common Omeprazole doses?

  • For frequent heartburn in adults: 20 mg taken once per day for 14 days

  • For symptomatic GERD in adults: 20 mg taken once per day for up to 4 weeks

  • For erosive esophagitis due to GERD in adults: 20 mg taken once per day for 4–8 weeks; maintenance treatment is 20 mg taken once per day for no longer than 12 months

  • For stomach ulcers in adults: 40 mg taken once per day for 4–8 weeks 

  • For duodenal ulcers in adults: 20 mg taken once per day for 4 weeks 

  • For H. pylori eradication in adults: 20 mg taken once per day for 10 days

  • For conditions that cause oversecretion of stomach acid in adults: 60–120 mg taken once per day

  • Children may also take prescription omeprazole for symptomatic GERD or erosive esophagitis. The dosages may be based on weight and age. Find more information about omeprazole dosages, forms, and strengths here.

Common Omeprazole prescriptions

  • Omeprazole
    1000 capsules delayed release bottle

  • Omeprazole
    14 tablets delayed release bottle

  • Omeprazole
    30 capsules delayed release bottle

  • Omeprazole
    500 capsules delayed release bottle

  • Omeprazole
    90 capsules delayed release bottle

  • Omeprazole
    14 tablets delayed release box

  • Omeprazole
    28 tablets delayed release box

  • Omeprazole
    42 tablets delayed release box

  • Omeprazole
    10mg capsule delayed release

  • Omeprazole
    20mg capsule delayed release

  • Omeprazole
    40mg capsule delayed release

How to take Omeprazole

  • The package instructions or your doctor will tell you how much medicine to use. Do not use more than directed.

  • Take this medicine before the first meal in the morning. 

  • Take this medicine for the full duration of treatment, even if you begin to feel better after a few days.

  • Do not take OTC omeprazole for more than 14 days or use the treatment more often than every 4 months unless your doctor tells you to.

  • This medicine should come with a Medication Guide or package insert. Ask your pharmacist for a copy if you do not have one.

  • HOW TO TAKE OMEPRAZOLE TABLETS AND CAPSULES

    • Swallow the tablet or capsule whole with a drink of water. Do not crush or chew it.

    • Swallow the OTC capsule whole. Do not crush or chew it.

    • If you cannot swallow a prescription omeprazole capsule, you may open it and pour the medicine into a small amount of applesauce. Stir this mixture well and swallow it without chewing. 

    • Store at room temperature protected from moisture.

  • HOW TO TAKE OMEPRAZOLE ORALLY DISINTEGRATING TABLETS 

    • Do not crush or chew the tablet.

    • Place the tablet on the tongue with or without water.

    • The tablet will disintegrate on the tongue.

    • Alternatively, the tablet can be swallowed whole with a glass of water.

    • Store at room temperature away from high heat and moisture.

  • HOW TO TAKE OMEPRAZOLE ORAL SUSPENSION 

    • Mix the contents of a 2.5-milligram (mg) packet with 5 milliliters (mL) of water or mix the contents of a 10-mg packet with 15 mL of water. Do not use other liquids or food.

    • Stir well. 

    • Let the mixture thicken for 2 to 3 minutes.

    • Stir again and drink the medicine within 30 minutes.

    • If there is any medicine left, add more water, stir, and drink immediately.

    • Store the sealed packets at room temperature.

  • HOW TO ADMINISTER OMEPRAZOLE ORAL SUSPENSION THROUGH A FEEDING TUBE

    • Add 5 mL of water to a catheter-tipped syringe for a 2.5 mg packet or 15 mL of water for a 10 mg packet. 

    • Then add the contents of the packet to the water.

    • Shake the syringe right away. 

    • Let the mixture thicken for 2 to 3 minutes.

    • Shake the syringe once more. 

    • Give the medicine through the tube within 30 minutes.

    • Refill the syringe with an equal amount of water and shake it. 

    • Use the water to flush the tube to make sure all the medicine is given.

What to do if you miss a dose of Omeprazole

  • 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.

Omeprazole contraindications

  • This medicine is not right for everyone. 

    Do not use omeprazole if you have had an allergic reaction to omeprazole or any other type of proton pump inhibitor.

Omeprazole warnings

  • Tell any doctor or other healthcare provider who treats you that you are using this medicine.

  • Your doctor may need lab tests at regular visits to check on the effects of this medicine, particularly if it’s taken continuously for several months. Keep all appointments.

  • Tell your doctor if you are pregnant or breastfeeding.

  • Before using OTC omeprazole, see a doctor if you have:

    • Trouble swallowing

    • Black and tarry stools

    • Blood in your vomit or stools

    • Stomach pain, nausea, and vomiting

    • Frequent chest pain

  • Before taking OTC or prescription omeprazole, tell a doctor if you have:

    • Kidney disease

    • Liver disease

    • Low levels of magnesium, potassium, or calcium

    • Osteoporosis

  • This medicine may cause the following problems:

    • Kidney problems

    • Increased risk of bone fractures, particularly in people with osteoporosis

    • Lupus or the worsening of lupus

    • Growths in the upper portion of the stomach

    • Vitamin B12 deficiency

    • Low magnesium

  • This medicine can cause C. difficile diarrhea that can occur 2 months or more after you stop taking this medicine. Call your doctor if you develop severe diarrhea, nonstop diarrhea, or bloody diarrhea. Do not take any medicine for diarrhea until you have talked to your doctor. 

  • Stop taking OTC omeprazole if:

    • Heartburn doesn’t improve or gets worse

    • You need to take omeprazole for longer than 14 days

    • You need to use omeprazole more than once in a four-month period

    • You get diarrhea

    • You get a skin rash or your joints start hurting

Omeprazole interactions

  • To avoid potentially hazardous drug interactions, tell the prescribing healthcare provider about all prescription drugs, over-the-counter medications, and supplements you are using before taking omeprazole.

  • Tell other healthcare providers you are using this medicine before they prescribe new medications.

  • Do not use omeprazole if you are also using HIV/AIDS medicines that contain the drug rilpivirine such as Edurant, Complera, Juluca, Cabenuva, or Odefsey.

  • Omeprazole should never be combined with the antibiotics amoxicillin or clarithromycin.

  • Omeprazole will affect other drugs. In some cases, omeprazole makes drugs less effective. In other cases, omeprazole can increase the risk of side effects from other drugs. Tell your doctor if you are using any of the following: 

    • Drugs that make you pee (diuretics)

    • Blood thinners, particularly warfarin and clopidogrel

    • Benzodiazepines, particularly diazepam

    • Iron supplements

    • Some cancer drugs

    • HIV/AIDS drugs, particularly rilpivirine

    • Anticancer drugs

    • The antifungal medications ketoconazole and itraconazole

    • The heart rhythm drug digoxin

    • The immune-suppressing drugs tacrolimus, cyclosporine, methotrexate, and mycophenolate mofetil

  • Some drugs can make omeprazole less effective. Tell the doctor if you are taking rifampin or St. John’s wort.

  • Omeprazole may interfere with some lab tests.

  • Find out more about omeprazole interactions to avoid here.

Omeprazole side effects

Serious side effects

Talk to a healthcare provider if you notice any signs or symptoms of possible serious side effects including:

  • Severe diarrhea, watery stools, bloody diarrhea, stomach pain that doesn’t go away

  • Decrease in how much you urinate, blood in the urine 

  • Seizures, dizziness, uneven heartbeat, muscle cramps or twitching

  • Hip, back, or wrist fracture

  • Joint pain, rash on your cheeks or arms that gets worse in the sun

  • Stomach pain, nausea, vomiting, weight loss

  • Blistering, peeling, red skin rash

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

Long-term use of omeprazole may cause serious side effects that may not have symptoms including:

  • Vitamin B12 deficiency

  • Low magnesium 

  • Stomach growths

Less serious side effects

  • Headache

  • Diarrhea

  • Stomach pain

  • Upper respiratory infections (in children)

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