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Drugs reference index «Omeprazole»



Brand names: Prilosec

Why is Omeprazole prescribed?

Prilosec is prescribed for the short-term treatment (4 to 8 weeks) of the following:

Stomach ulcer

Duodenal ulcer (near the exit from the stomach)

Erosive esophagitis (inflammation of the esophagus)

Heartburn and other symptoms of gastroesophageal reflux disease (also known as GERD, which occurs when stomach acid backs up into the tube connecting the throat to the stomach).

It is also used to maintain healing of erosive esophagitis and for the long-term treatment of conditions in which too much stomach acid is secreted, including Zollinger-Ellison syndrome, multiple endocrine adenomas (benign tumors), and systemic mastocytosis (cancerous cells).

Combined with the antibiotic clarithromycin (and sometimes with the antibiotic amoxicillin as well), Prilosec is also used to cure patients whose ulcers are caused by infection with the germ H. pylori.

In addition, Prilosec is available as an over-the-counter (OTC) product. However, Prilosec OTC is approved only for treating frequent heartburn (occurs two or more days a week). The prescription version is still needed for treatment of ulcers, esophagitis, GERD, and other conditions that require monitoring by a doctor.

Most important fact about Omeprazole

Prilosec's healing effect can mask the signs of stomach cancer. Your doctor should be careful to rule out this possibility.

How should you take Omeprazole?

Prilosec works best when taken before meals. It can be taken with an antacid.

The capsule should be swallowed whole. It should not be opened, chewed, or crushed.

If you have difficulty swallowing capsules, you can empty the contents of the Prilosec capsule onto a tablespoonful of applesauce, mix, and swallow with a glass of cool water. Use cool, soft applesauce and do not chew or crush the pellets. Use the mixture immediately. Do not store it for future use.

Avoid excessive amounts of caffeine while taking Omeprazole.

It may take several days for Prilosec to begin relieving stomach pain. Be sure to continue taking the drug exactly as prescribed even if it seems to have no effect.

  • If you miss a dose...Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Do not take 2 doses at once.
  • Storage information...Store at room temperature in a tightly closed container, away from light and moisture.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Prilosec.

  • Side effects may include:Abdominal pain, diarrhea, headache, nausea, vomiting
  • When taken with clarithromycin, side effects may also include:Flu symptoms, nasal inflammation, sore throat, taste alteration, tongue discoloration
  • When taken with amoxicillin and clarithromycin, side effects may also include:Diarrhea, headache, taste alteration

Why should Omeprazole not be prescribed?

If you are sensitive to or have ever had an allergic reaction to Prilosec or any of its ingredients, you should not take Omeprazole. Make sure your doctor is aware of any drug reactions you have experienced.

You should avoid the Prilosec/clarithromycin combination treatment if you are allergic to certain antibiotics called macrolides.

Special warnings about Omeprazole

Long-term use of Omeprazole can cause severe stomach inflammation.

Possible food and drug interactions when taking Omeprazole

If Prilosec is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Prilosec with the following:

Ampicillin-containing drugsCyclosporineDiazepamDisulfiramIronKetoconazolePhenytoinWarfarin

Special information if you are pregnant or breastfeeding

The effects of Prilosec during pregnancy have not been adequately studied. If you are pregnant or plan to become pregnant, inform your doctor immediately. Avoid combined therapy with clarithromycin unless there is no alternative. Prilosec (and clarithromycin) may appear in breast milk and could affect a nursing infant. If Omeprazole is essential to your health, your doctor may advise you to discontinue breastfeeding until your treatment with Omeprazole is finished.

Recommended dosage


Short-term Treatment of Active Duodenal Ulcer

The usual dose is 20 milligrams once a day. Most people heal within 4 weeks, although some require an additional 4 weeks of Prilosec therapy.

Treatment of Duodenal Ulcers Caused by H. Pylori

In combination therapy with clarithromycin alone, the usual dosage is 40 milligrams of Prilosec once daily and 500 milligrams of clarithromycin 3 times a day for 14 days, followed by 20 milligrams of Prilosec once daily for an additional 14 days.

If amoxicillin is included in the treatment, the recommended dosage is 20 milligrams of Prilosec, 500 milligrams of clarithromycin, and 1,000 milligrams of amoxicillin twice a day for 10 days, followed by 20 milligrams of Prilosec once daily for an additional 18 days.

Gastric Ulcer

The usual dose is 40 milligrams once a day for 4 to 8 weeks.

Gastroesophageal Reflux Disease (GERD)

The usual dose for people with symptoms of GERD is 20 milligrams daily for up to 4 weeks. For erosive esophagitis accompanied by GERD symptoms, the usual dose is 20 milligrams a day for 4 to 8 weeks.

The dose may be continued to maintain healing.

Pathological Hypersecretory Conditions

The usual starting dose is 60 milligrams once a day. If you take more than 80 milligrams a day, your doctor will divide the total into smaller doses. The dosing will be based on your needs.


Gastroesophageal Reflux Disease (GERD) and Acid-Related Disorders

For children weighing less than 44 pounds, the usual dose is 10 milligrams a day. For those weighing 44 pounds or more, the usual dose is 20 milligrams a day. For children with erosive esophagitis, your doctor will determine the correct dose based on the child's weight.

The safety and effectiveness of Prilosec have not been studied in children under 2 years old.


Do not give Prilosec OTC to children under 18 years old unless your doctor approves. Prilosec OTC is used to treat frequent heartburn (occurs 2 or more days a week). It is not intended for immediate relief of heartburn, and it may take 1 to 4 days before you start noticing the drug's full effect.

Swallow tablets with a glass of water before eating in the morning. Do not chew or crush the tablets. The recommended dose is 1 tablet every day for 14 days. Do not take more than 1 tablet a day, and do not use for more than 14 days unless your doctor approves. If needed, you may repeat the 14-day course of treatment every 4 months. Do not repeat the treatment more often than every 4 months unless your doctor approves.


Overdose with Prilosec has been rare, but any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.

  • Symptoms of Prilosec overdose may include:Blurred vision, confusion, drowsiness, dry mouth, flushing, headache, nausea, rapid, heartbeat, sweating, vomiting
  • Omeprazole Delayed-Release Capsules MedFacts Consumer Leaflet (Wolters Kluwer)
  • Omeprazole Professional Patient Advice (Wolters Kluwer)
  • omeprazole Advanced Consumer (Micromedex) - Includes Dosage Information
  • Omeprazole Prescribing Information (FDA)
  • Prilosec Consumer Overview
  • Prilosec Prescribing Information (FDA)
  • Prilosec OTC Delayed-Release Tablets MedFacts Consumer Leaflet (Wolters Kluwer)

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