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Generic Name:

omeprazole, Oral capsule, sprinkles

All Brands

  • Prilosec
SECTION 1 of 5

Highlights for omeprazole

Oral capsule, sprinkles
1

Omeprazole is used to reduce the amount of acid in your stomach. It’s used to treat gastric or duodenal ulcers, gastroesophageal reflux disease (GERD), erosive esophagitis (inflammation in the esophagus), and hypersecretory conditions (conditions where your stomach makes too much acid). This drug is also used to treat stomach infections caused by the bacteria Helicobacter pylori.

2

This drug comes in the form of a capsule or liquid suspension you take by mouth.

3

Omeprazole is available as the brand-name drug Prilosec. It’s also available as a generic drug.

4

The more common side effects of this drug include headache, stomach pain, nausea, diarrhea, vomiting, and gas.

5

In some cases, omeprazole can cause serious side effects. These include an increased risk of bone fractures or low magnesium levels in your body. These serious side effects are more likely if you take the drug longer than 3 months.

IMPORTANT INFORMATION

Vitamin B-12 deficiency

Omeprazole reduces the amount of acid in your stomach. Your body needs stomach acid to absorb vitamin B-12. Taking this drug for 3 years or longer can make it harder for your body to absorb vitamin B-12. This can lead to a vitamin B-12 deficiency.

Severe diarrhea

This drug may increase your risk of severe diarrhea. This may be caused by an infection in your intestine caused by the bacteria Clostridium difficile. Call your doctor right away if you have watery diarrhea, stomach pain, and a fever that won’t go away.

Bone fractures

People who take several doses of a proton pump inhibitor drug, such as omeprazole, every day for a year or longer may have an increased risk of bone fractures. These bone breaks may be more likely to happen in your hip, wrist, or spine. Talk to your doctor about your risk of bone fractures. You should take this drug exactly as prescribed by your doctor. They should prescribe the lowest dose possible for the shortest amount of time needed for your treatment.

Low magnesium levels

Taking this drug for 3 months or longer can cause low magnesium levels in your body. Your risk is higher if you take omeprazole for a year or longer. Call your doctor right away if you have symptoms of low magnesium. These can include seizures, abnormal or fast heart rate, jitteriness, jerking movements or shaking, and muscle weakness. They can also include cramps or muscle aches and spasms of your hands, feet, and voice box. Your doctor may check your magnesium levels before and during your treatment with this drug.

What is omeprazole?

Omeprazole is a prescription and over-the-counter drug. Prescription omeprazole is available as a delayed-release oral capsule or delayed-release oral suspension. A delayed-release drug slows the release of the medication until it passes through your stomach. This delay keeps the drug from being inactivated by your stomach.

Omeprazole is available as the brand-name drug Prilosec and as a generic drug. Generic drugs usually cost less. The forms differ between the generic and the brand-name version.

This drug may be used as part of a combination therapy. This means you may need to take it with other medications.

Why it's used

Omeprazole is used to treat conditions caused by too much acid production in the stomach.

More Details

How it works

Omeprazole belongs to a class of drugs called proton pump inhibitors (PPIs).

More Details

Why it's used

Omeprazole is used to treat conditions caused by too much acid production in the stomach, such as:

  • Gastroesophageal reflux disease (GERD)
  • Erosive esophagitis (acid-related damage to the esophagus, the tube that connects your mouth to your stomach)
  • Gastric (stomach) ulcers or duodenal ulcers. Duodenal ulcers occur in your duodenum. This is the first part of your small intestine. It is the part connected to your stomach.
  • Conditions where your stomach makes too much acid, such as Zollinger-Ellison Syndrome
  • Stomach infections caused by Helicobacter pylori

How it works

Omeprazole belongs to a class of drugs called proton pump inhibitors (PPIs). A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

Omeprazole works by decreasing the amount of acid your stomach produces. It does this by blocking the proton pump in the cells of your stomach. The proton pump works in the final step of acid production. When the proton pump is blocked, your stomach makes less acid. This should decrease your symptoms.

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SECTION 2 of 5

omeprazole Side Effects

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More common side effects

The side effects from this drug are slightly different for children and adults.

  • Adult side effects can include:

    • headache
    • stomach pain
    • nausea
    • diarrhea
    • vomiting
    • gas
  • Children’s side effects can include the above, plus the following:

    • fever

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Call 9-1-1 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • Low magnesium levels. Using this drug for 3 months or longer can cause low magnesium levels. Symptoms can include:

    • seizures
    • abnormal or fast heart rate
    • tremors
    • jitteriness
    • muscle weakness
    • dizziness
    • spasms of your hands and feet
    • cramps or muscle aches
    • spasm of your voice box
  • Vitamin B-12 deficiency. Using this drug for longer than 3 years can make it harder for your body to absorb vitamin B-12. Symptoms can include:

    • nervousness
    • neuritis (inflammation of a nerve)
    • numbness or tingling in your hands and feet
    • poor muscular coordination
    • changes in menstruation
  • Severe diarrhea. This may be caused by a Clostridium difficile infection in your intestines. Symptoms can include:

    • watery stool
    • stomach pain
    • fever that doesn’t go away
  • Inflammation of your stomach lining. Symptoms can include:

    • stomach pain
    • nausea
    • vomiting
    • weight loss
  • Bone fractures

  • Kidney damage. Symptoms can include:

    • flank pain (pain in your side and back)
    • changes in urination 
Pharmacist's Advice
Clinical Associate Professor, University of Illinois at Chicago College of Pharmacy

Omeprazole doesn’t cause drowsiness.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
SECTION 3 of 5

omeprazole May Interact with Other Medications

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Omeprazole can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Medications that might interact with this drug

Drugs you should not use with omeprazole

Do not take these drugs with omeprazole. Doing so can cause dangerous effects in the body. Examples of these drugs include:

  • Atazanavir and nelfinavir. Omeprazole may greatly decrease the effects of these drugs and could make them less effective over time. You shouldn’t take these drugs with omeprazole.

Interactions that increase the risk of side effects
  • Side effects from omeprazole: Taking omeprazole with certain medications raises your risk of side effects from omeprazole. This is because the amount of omeprazole in your body is increased. Examples of these drugs include:
    • Voriconazole. This drug may increase the levels of omeprazole in your body. If you’re taking high doses of omeprazole, your doctor may adjust your omeprazole dose.
  • Side effects from other drugs: Taking omeprazole with certain medications raises your risk of side effects from these drugs. Examples of these drugs include:
    • Saquinavir. Omeprazole may greatly increase the levels of saquinavir in your body. Your doctor may lower your dose of saquinavir.
    • Digoxin. Omeprazole may increase the levels of digoxin in your body. Your doctor may monitor the levels of digoxin in your blood.
    • Warfarin. Omeprazole may increase the levels of warfarin in your body. Your doctor may monitor you for symptoms of bleeding.
    • Phenytoin. Omeprazole may increase the levels of phenytoin in your body. Your doctor may watch you for high levels of phenytoin.
    • Cilostazol. Omeprazole may increase the levels of cilostazol in your body. Your doctor may lower your dose of cilostazol.
    • Tacrolimus. Omeprazole may increase the levels of tacrolimus in your body. Your doctor may monitor the level of tacrolimus in your body.
    • Methotrexate. Omeprazole may increase the effects of methotrexate. Your doctor may adjust your dose depending on the levels of methotrexate in your body.
    • Diazepam. Omeprazole may increase the levels of diazepam in your body. Your doctor may watch you for more side effects from diazepam.
    • Benzodiazepines. Your doctor will monitor you while you’re taking these drugs with omeprazole. Your doctor may change your dose. 

Interactions that can make your drugs less effective
  • When other drugs are less effective: When certain drugs are used with omeprazole, they may not work as well. This is because the amount of these drugs in your body may be decreased. Examples of these drugs include:
    • Ampicillin esters. Omeprazole can keep your body from absorbing antibiotics like ampicillin well. Ampicillin may not work as well to treat your infection.
    • Ketoconazole. Omeprazole can keep your body from absorbing ketoconazole well. Ketoconazole may not work as well to treat your infection.
    • Mycophenolate mofetil (MMF). Omeprazole can keep your body from absorbing MMF well. MMF may not work as well. It isn’t known how this may affect your risk of organ rejection. If you take MMF, ask your doctor if dexlansoprazole is safe for you to take.
    • Iron salts. Omeprazole can keep your body from fully absorbing drugs that contain iron.
    • Erlotinib. Omeprazole can keep your body from absorbing erlotinib well. Erlotinib may not work as well to treat your cancer.
    • Clopidogrel. Omeprazole may make clopidogrel work less well.
  • When omeprazole is less effective: When omeprazole is used with certain drugs, it may not work as well to treat your condition. This is because the amount of omeprazole in your body may be decreased. Examples of these drugs include:
    • St. John’s wort
    • Rifampin

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Important considerations for taking omeprazole
liver problem warning
People with liver problems

This drug may change the way your liver works. If you have severe liver problems, your doctor may decrease your dose.

stomach acid warning
People with a vitamin B-12 deficiency

This drug reduces the amount of acid in your stomach. You need stomach acid to absorb vitamin B-12. If you’ve been taking this drug for more than 3 years, talk to your doctor. Your doctor may monitor your vitamin B-12 levels and give you vitamin B-12 injections if needed.

osteoporosis warning
People with osteoporosis

People who take multiple doses of this drug every day for a year or longer may have an increased risk of fractures. These fractures may be more likely to happen in your hip, wrist, or spine. If you already have osteoporosis, you already have an increased risk of bone fractures.

low magnesium warning
People with low magnesium levels in the blood

This drug can cause low magnesium levels if you’ve been taking it for 3 months or longer. Having low magnesium levels can be serious. Your doctor will monitor your magnesium levels during your treatment with this drug and give you supplements if needed.

pregnancy warning
Pregnant women

Omeprazole is a category C pregnancy drug. That means two things:

  1. Research in animals has shown adverse effects to the fetus when the mother takes the drug.
  2. There haven’t been enough studies done in humans to be certain how the drug might affect the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should only be used if the potential benefit justifies the potential risk to the fetus.

breast feeding warning
Women who are breast-feeding

Omeprazole passes into breast milk and may cause side effects in a child who is breastfed.

Talk to your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this medication.

senior warning
For seniors

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

childrens warning
For children

This drug hasn’t been studied in children with duodenal ulcers, gastric ulcers, or hypersecretory conditions. It shouldn’t be used in people younger than 16 years for these conditions.

This drug hasn’t been shown to be safe or effective in children younger than 2 years with gastroesophageal reflux disease (GERD). It shouldn’t be used in people younger than 2 years for this condition.

This drug hasn’t been shown to be safe or effective in children younger than 1 year with erosive esophagitis. It shouldn’t be used in people younger than 1 year for this condition.

call the doctor
When to call the doctor

Call your doctor right away if you become pregnant while taking this drug.

Call your doctor if your symptoms aren’t getting better while you’re taking this drug. This drug starts working within a few hours, but it may take weeks to see total healing.

allergy warning
Allergies

Omeprazole can cause a severe allergic reaction. Symptoms can include:

  • rash
  • face swelling
  • throat tightness
  • trouble breathing

If you have an allergic reaction, call your doctor or local poison control center right away. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it or other proton pump inhibitors. Taking it again could be fatal (cause death).

SECTION 4 of 5

How to Take omeprazole (Dosage)

Oral capsule, sprinkles

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Duodenal ulcer or stomach infection

Generic: Omeprazole

Form: delayed-release oral capsule
Strengths: 10 mg, 20 mg, 40 mg

Brand: Prilosec

Form: delayed-release oral suspension
Strengths: 2.5 mg, 10 mg
Adult dosage (ages 18 years and older)

For an active duodenal ulcer:

  • 20 mg taken once per day for up to 4 weeks. Some people may need more than 4 weeks of treatment.

For a duodenal ulcer that is caused by Helicobacter pylori infection:

  • 20 mg taken twice per day for 10 days with amoxicillin and clarithromycin
  • 40 mg taken once per day for 14 days with clarithromycin
Child dosage (ages 16–17 years)

For an active duodenal ulcer:

  • 20 mg taken once per day for up to 4 weeks. Some people may need more than 4 weeks of treatment.

For a duodenal ulcer that is caused by Helicobacter pylori infection:

  • 20 mg taken twice per day for 10 days with amoxicillin and clarithromycin
  • 40 mg taken once per day for 14 days with clarithromycin
Child dosage (ages 0–15 years)

This drug hasn’t been studied in children. It shouldn’t be used in people younger than 16 years.

Special considerations

People of Asian descent. Your doctor may give you a lower dose of this medication, especially if you’re taking it for erosive esophagitis.

Gastric (stomach) ulcer

Generic: Omeprazole

Form: delayed-release oral capsule
Strengths: 10 mg, 20 mg, 40 mg

Brand: Prilosec

Form: delayed-release oral suspension
Strengths: 2.5 mg, 10 mg
Adult dosage (ages 18 years and older)

40 mg taken once per day for 4–8 weeks

Child dosage (ages 16–17 years)

40 mg taken once per day for 4–8 weeks

Child dosage (ages 016 years)

This drug hasn’t been studied in children younger than 16 years. It shouldn’t be used in people younger than 16 years.

Special considerations

People of Asian descent. Your doctor may give you a lower dose of this medication, especially if you’re taking it for erosive esophagitis.

Gastroesophageal reflux disease (GERD)

Generic: Omeprazole

Form: delayed-release oral capsule
Strengths: 10 mg, 20 mg, 40 mg

Brand: Prilosec

Form: delayed-release oral suspension
Strengths: 2.5 mg, 10 mg
Adult dosage (ages 18 years and older)
  • Gastroesophageal reflux disease (GERD): 20 mg taken once per day for 4–8 weeks
  • Esophagitis with GERD symptoms: 20 mg taken once per day for 4–8 weeks
Child dosage (ages 17 years)
  • Gastroesophageal reflux disease (GERD): 20 mg taken once per day for 4–8 weeks
  • Esophagitis with GERD symptoms: 20 mg taken once per day for 4–8 weeks
Child dosage (ages 2–16 years)

Your dose will be based on your weight:

  • 5 kg to less than 10 kg (11 lb to less than 22 lb): 5 mg taken once per day
  • 10 kg to less than 20 kg (22 lb to less than 44 lb): 10 mg taken once per day
  • 20 kg (44 lb) or more: 20 mg taken once per day
Child dosage (ages 0–1 year)

This drug hasn’t been studied in children younger than 2 years. It shouldn’t be used in people younger than 2 years.

Special considerations

People of Asian descent. Your doctor may give you a lower dose of this medication, especially if you’re taking it for erosive esophagitis.

Erosive esophagitis

Generic: Omeprazole

Form: delayed-release oral capsule
Strengths: 10 mg, 20 mg, 40 mg

Brand: Prilosec

Form: delayed-release oral suspension
Strengths: 2.5 mg, 10 mg
Adult dosage (ages 18 years and older)

20 mg taken once per day

Child dosage (ages 17 years)

20 mg taken once per day

Child dosage (ages 1–16 years)

Your dose will be based on your weight:

  • 5 kg to less than 10 kg (11 lb to less than 22 lb): 5 mg taken once per day
  • 10 kg to less than 20 kg (22 lb to less than 44 lb): 10 mg taken once per day
  • 20 kg (44 lb) or more: 20 mg taken once per day
Child dosage (ages 0–11 months)

This drug hasn’t been studied in children younger than 1 year. It shouldn’t be used in people younger than 1 year.

Special considerations

People of Asian descent. Your doctor may give you a lower dose of this medication, especially if you’re taking it for erosive esophagitis.

Pathological hypersecretory conditions

Generic: Omeprazole

Form: delayed-release oral capsule
Strengths: 10 mg, 20 mg, 40 mg

Brand: Prilosec

Form: delayed-release oral suspension
Strengths: 2.5 mg, 10 mg
Adult dosage (ages 18 and older)
  • Typical starting dose: 60 mg taken once per day
  • Dose increases: Your doctor will increase your dose as needed.
  • Maximum dose: 360 mg per day. If you need to take more than 80 mg per day, your doctor will have you take it in divided doses.
Child dosage (ages 16–17 years)
  • Typical starting dose: 60 mg taken once per day
  • Dose increases: Your doctor will increase your dose as needed.
  • Maximum dose: 360 mg per day. If you need to take more than 80 mg per day, your doctor will have you take it in divided doses.
Child dosage (ages 0–15 years)

This drug hasn’t been studied in children younger than 16 years. It shouldn’t be used in people younger than 16 years.

Special considerations

People of Asian descent. Your doctor may give you a lower dose of this medication, especially if you’re taking it for erosive esophagitis.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Clinical Associate Professor, University of Illinois at Chicago College of Pharmacy

Omeprazole comes with serious risks if you don’t take it as prescribed.

If you stop taking the drug suddenly or don’t take it at all

Your acid reflux, heartburn, or ulcer symptoms may not improve. They may even get worse.

If you miss doses or don’t take the drug on schedule

Your medication may not work as well or may stop working completely.

If you take too much

You could have dangerous levels of the drug in your body. Symptoms can include:

  • confusion
  • drowsiness
  • blurred vision
  • fast heart rate
  • nausea
  • vomiting
  • sweating
  • flushing
  • headache
  • dry mouth

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room right away.

What to do if you miss a dose

Take your dose as soon as you remember. If you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.

How to tell if the drug is working

You should have decreased pain and acid reflux symptoms.

Omeprazole is used for short-term treatment of duodenal and gastric ulcers and gastroesophageal reflux disease (GERD).

Omeprazole is used for long-term treatment of erosive esophagitis and pathological hypersecretory conditions.

Important considerations for taking omeprazole
not with food
Take this drug on an empty stomach
timing considerations
Take this drug at the time(s) recommended by your doctor, at least 1 hour before a meal
do not crush
Don’t chew or crush the capsules
See Details
storage considerations
Store this drug carefully
See Details
prescription is refillable
A prescription for this medication is refillable
See Details
travel considerations
Travel
See Details
self management considerations
Self-management
See Details
clinical monitoring considerations
Clinical monitoring
See Details
not usually stocked
Not every pharmacy stocks this drug. When filling your prescription, be sure to call ahead.
prior authorization needed
Insurance
See Details

Don’t chew or crush the capsules

You should swallow capsules whole. If you have trouble swallowing it, you can open the capsule and empty its contents (pellets) onto 1 tablespoon of applesauce. Mix the pellets with the applesauce. Swallow the mixture right away with a glass of cool water. Don’t chew or crush the pellets. Don’t store the mixture for later use.

Store this drug carefully

Delayed-released oral capsule:

  • Store the delayed-release oral capsules at room temperature. Keep them between 59°F and 86°F (15°C and 30°C).
  • Keep this medication away from light.
  • Don’t store this medication in moist or damp areas, such as bathrooms.

Oral suspension:

  • Store the oral suspension at room temperature at 77°F (25°C). You can store it briefly between 59°F and 86°F (15°C and 30°C).

A prescription for this medication is refillable

You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport x-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Self-management

Your doctor or pharmacist will show you how to take the oral suspension.

The oral suspension may also be given through a nasogastric tube or gastric tube as prescribed by your doctor. Talk to your doctor or pharmacist about how to give the oral suspension through a tube.

Clinical monitoring

Your doctor should monitor certain health issues. This can help make sure you stay safe while you take this drug. These issues include:

  • Liver function. Your doctor may do blood tests to check how well your liver is working. If your liver isn’t working well, your doctor may lower your dose of this drug.
  • Magnesium levels. Your doctor may do blood tests to check how high your magnesium levels are. If your magnesium levels are too high, your doctor may lower your dose or have you stop taking this drug.

Insurance

Many insurance companies require a prior authorization for this drug. This means your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

SECTION 5 of 5

How Much Does omeprazole Cost?

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Lowest price for omeprazole

Safeway $7.55
Walmart $9.23
Sams Club $9.23
These prices represent the lowest priced national pharmacies for omeprazole on GoodRx. They may be lower than your insurance.

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These prices represent the lowest priced national pharmacies for omeprazole on GoodRx. They may be lower than your insurance.

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Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on September 21, 2016

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
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