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Medical and Pharmacy Editor:

Brand Name: Prilosec, Prilosec OTC

Generic Name: omeprazole

Drug Class: Proton Pump Inhibitors

What Is Omeprazole and How Does It Work?

Omeprazole, approved by the FDA, is available as a prescription and over-the-counter (OTC) drug used as a treatment for frequent heartburn.

Heartburn is a very common symptom caused by acid reflux. Acid reflux is a medical condition where stomach contents and stomach acid are forced backwards into the esophagus. This creates a sensation of burning and pain in the chest. A doctor sees a patient who complains of suffering from acid reflux (heartburn) at least twice per week, the diagnosis of gastroesophageal reflux disease or GERD is made.

This drug is also used as a treatment of other conditions such as the management of 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.

Omeprazole may help your stomach symptoms related to acid, but you could still have serious stomach problems. This medication may increase your risk of severe diarrhea. This diarrhea may be caused by an infection (Clostridium difficile) in your intestines. Call your medical professional or seek medical help right away if you have watery stools, stomach pain, or fever.

Omeprazole is available under the following different brand names: Prilosec, and Prilosec OTC.

This drug is available as a capsule or oral liquid suspension. This drug is available by prescription as a delayed-release oral capsule or delayed-release oral suspension.

Dosages of Omeprazole

Adult & Pediatric Dosages:

Tablet: Schedule IV


  • 2.5 mg
  • 10 mg


  • 2 mg/ml

Tablet, delayed release (adult dosage only)

    20 mg

Capsule, delayed release

  • 10 mg
  • 20 mg
  • 40 mg

Dosage Considerations of Omeprazole

Duodenal Ulcer

  • 20 mg orally each day for 4-8 weeks
  • Safety and efficacy for maintenance treatment past 1 year not established.

Helicobacter Pylori Infection

Various regimens exist of proton pump inhibitors (PPIs) combined with antibiotics for patients who have failed therapy. See the example is listed below:

  • 20 mg orally every 12 hours for 10 days, WITH Amoxicillin 1000 mg orally every 12 hours, AND Clarithromycin 500 mg orally every 12 hours for 10-14 days

Gastric Ulcer

  • 40 mg orally every day for 4-8 weeks


  • Adult: 20 mg orally every day for 4 weeks
  • Children less than 1 year old: Safety and efficacy not established
  • Children 5-10 kg: 5 mg orally once per day
  • Children 10-20 kg: 10 mg orally once per day
  • Children greater than 20 kg: 20 mg once per day

Erosive Esophagitis

  • Adult: 20 mg orally every day for 4-8 weeks
  • Adult: Maintenance: 20 mg orally daily for up to 1 year

Pediatric Treatment

Children less than 1 month: Safety and efficacy not established

Children aged 1 month to over 1 year:

  • 3 to 5 kg: 2.5 mg once daily
  • 5 to 10 kg: 5 mg once daily
  • 10 kg or greater: 10 mg once daily

May treat for up to 6 weeks

May treat for 4-8 weeks

Maintenance of healing

Under 1 year: Safety and efficacy not established

1 year or older: Controlled trials for maintenance do not extend beyond 12 months.

Neonates (Off-label)

Refractory duodenal ulcer or reflux esophagitis: 0.5-1.5 mg/kg orally once daily for up to 8 weeks.

Hypersecretory Condition (Zollinger-Ellison Syndrome)

60 mg orally daily (initial) up to 360 mg/day divided into every 8 hours orally.

If dose is greater than 80 mg, divide it.

Dosage Modifications

Hepatic impairment: Not studied; expert analysis recommends a reduction in dose, especially for maintenance of healing of erosive esophagitis.

Renal impairment: Dose adjustments is not necessary.

Medically Reviewed by a Doctor on 4/3/2017

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