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Omeprazole

Generic Name: omeprazole (oh MEP ra zol)
Brand Names: FIRST Omeprazole, Omeprazole + SyrSpend SF Alka, PriLOSEC

Medically reviewed: April 8, 2018

What is omeprazole?

Omeprazole is a proton pump inhibitor that decreases the amount of acid produced in the stomach.

Omeprazole is used to treat symptoms of gastroesophageal reflux disease (GERD) and other conditions caused by excess stomach acid. It is also used to promote healing of erosive esophagitis (damage to your esophagus caused by stomach acid).

Omeprazole may also be given together with antibiotics to treat gastric ulcer caused by infection with helicobacter pylori (H. pylori).

Over-the-counter (OTC) omeprazole is used to help control heartburn that occurs 2 or more days per week. This medicine not for immediate relief of heartburn symptoms. OTC omeprazole must be taken on a regular basis for 14 days in a row.

Important Information

Omeprazole is not for immediate relief of heartburn symptoms.

Heartburn is often confused with the first symptoms of a heart attack. Seek emergency medical attention if you have chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, and a general ill feeling.

You should not take this medication if you are allergic to omeprazole or to any other benzimidazole medication such as albendazole or mebendazole.

Ask a doctor or pharmacist if it is safe for you to take omeprazole if you have liver disease or heart disease, or low levels of magnesium in your blood.

Some conditions are treated with a combination of omeprazole and antibiotics. Use all medications as directed by your doctor. Read the medication guide or patient instructions provided with each medication. Do not change your doses or medication schedule without your doctor's advice.

Take omeprazole for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared.

Prilosec OTC (over-the-counter) should be taken for no longer than 14 days in a row. Allow at least 4 months to pass before you start another 14-day treatment.

Before taking this medicine

Heartburn can mimic early symptoms of a heart attack. Get emergency medical help if you have chest pain that spreads to your jaw or shoulder and you feel anxious or light-headed.

You should not use omeprazole if you are allergic to it, or if:

Ask a doctor or pharmacist if it is safe for you to use omeprazole if you have other medical conditions, especially:

You may be more likely to have a broken bone in your hip, wrist, or spine while taking a proton pump inhibitor. Talk with your doctor about ways to keep your bones healthy.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Do not use this medicine without a doctor's advice if you are breast-feeding.

Do not give this medicine to a child without medical advice.

How should I take omeprazole?

Omeprazole is usually taken before eating (at least 1 hour before a meal). Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Use Prilosec OTC (over-the-counter) exactly as directed on the label, or as prescribed by your doctor.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

Shake the oral suspension (liquid) before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

If you cannot swallow a capsule whole, open it and sprinkle the medicine into a spoonful of applesauce. Swallow the mixture right away without chewing. Do not save it for later use.

You must dissolve omeprazole powder in a small amount of water. This mixture can either be swallowed or given through a nasogastric (NG) feeding tube using a catheter-tipped syringe.

OTC omeprazole should be taken for only 14 days in a row. Allow at least 4 months to pass before you start a new 14-day course of treatment.

Use this medicine for the full prescribed length of time, even if your symptoms quickly improve.

Taking omeprazole long-term could cause you to develop a vitamin B-12 deficiency. Talk to your doctor about how to manage this condition.

Call your doctor if your symptoms do not improve, or if they get worse.

Some conditions are treated with a combination of omeprazole and antibiotics. Use all medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice.

This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using omeprazole.

Store at room temperature away from moisture and heat.

Omeprazole dosing information

Usual Adult Dose for Duodenal Ulcer:

20 mg orally once a day before a meal. Most patients heal within 4 to 8 weeks.

Usual Adult Dose for Helicobacter pylori Infection:

Dual therapy: omeprazole 40 mg orally once a day in the morning plus clarithromycin 500 mg orally 3 times a day on days 1 to 14. Beginning on day 15, omeprazole 20 mg orally once a day in the morning on days 15 to 28.

Triple therapy: omeprazole 20 mg plus clarithromycin 500 mg plus amoxicillin 1000 mg all given orally twice a day for 10 days. If an ulcer is present at the initiation of therapy, continue omeprazole 20 mg orally once a day for an additional 18 days.

Study (n=294) - Canadian Adult Dyspepsia Empiric Treatment-Helicobacter pylori positive (CADET-Hp): omeprazole 20 mg, metronidazole 500 mg, and clarithromycin 500 mg, twice daily for 7 days.

Usual Adult Dose for Gastric Ulcer:

40 mg orally once a day before a meal for 4 to 8 weeks.

Usual Adult Dose for Erosive Esophagitis:

20 mg orally once a day before a meal. This dosage may be increased to 40 mg per day based on desired clinical response and patient tolerance. Studies have been completed up to 12 months for maintenance therapy of erosive esophagitis.

Usual Adult Dose for Zollinger-Ellison Syndrome:

Initial: 60 mg orally once a day. Dosage should be individualized to patient's needs.

Maintenance: doses up to 120 mg 3 times a day have been administered. Daily doses greater than 80 mg should be divided.

Usual Adult Dose for Gastroesophageal Reflux Disease:

Initial: 20 mg orally once a day before a meal for 4 to 8 weeks. This dosage may be increased to 40 mg per day if needed.

Maintenance: long-term treatment with doses of 10 to 20 mg per day may be required for maintenance therapy of refractory disease and appears to be safe.

Usual Adult Dose for Multiple Endocrine Adenomas:

Initial: 60 mg orally once a day before a meal. This dosage may be titrated based on desired clinical response and patient tolerance.

Maintenance: doses up to 120 mg 3 times a day have been administered. Daily doses greater than 80 mg should be divided.

Usual Adult Dose for Systemic Mastocytosis:

Initial: 60 mg orally once a day before a meal. This dosage may be titrated based on desired clinical response and patient tolerance.

Maintenance: doses up to 120 mg 3 times a day have been administered. Daily doses greater than 80 mg should be divided.

Usual Adult Dose for Dyspepsia:

Prevention of frequent heartburn: 20 mg orally once daily, before a meal, for 14 days.

Usual Pediatric Dose for Erosive Esophagitis:

Oral:
Infants:
GERD: 0.7 mg/kg/dose once daily reduced the percentage of time gastric and esophageal pH less than 4, as well as the number of reflux episodes in 10 neonates [mean PMA: 36.1 weeks, (34 to 40 weeks)] in a trial. Higher doses of 1 to 1.5 mg/kg/day have been reported

Children and Adolescents 1 to 16 years:
GERD, ulcers, esophagitis:
Manufacturer recommendations:
5 kg to less than 10 kg: 5 mg once daily
10 kg to less than or equal to 20 kg: 10 mg once daily
Greater than 20 kg: 20 mg once daily

Alternate dosing:
Children 1 to 16 years:
1 mg/kg/dose once or twice daily

Adjunctive therapy of duodenal ulcers associated with Helicobacter pylori (in combination with antibiotic therapy either clarithromycin or clarithromycin and amoxicillin) in children:
15 to 30 kg: 10 mg twice daily
Greater than 30 kg: 20 mg twice daily

Comment: The safety and efficacy of omeprazole use in patients less than 1 year of age and for pediatric uses other than the treatment of GERD and maintenance of healing of erosive esophagitis has not been established.

Usual Pediatric Dose for Gastroesophageal Reflux Disease:

Oral:
Infants:
GERD: 0.7 mg/kg/dose once daily reduced the percentage of time gastric and esophageal pH less than 4, as well as the number of reflux episodes in 10 neonates [mean PMA: 36.1 weeks, (34 to 40 weeks)] in a trial. Higher doses of 1 to 1.5 mg/kg/day have been reported

Children and Adolescents 1 to 16 years:
GERD, ulcers, esophagitis:
Manufacturer recommendations:
5 kg to less than 10 kg: 5 mg once daily
10 kg to less than or equal to 20 kg: 10 mg once daily
Greater than 20 kg: 20 mg once daily

Alternate dosing:
Children 1 to 16 years:
1 mg/kg/dose once or twice daily

Adjunctive therapy of duodenal ulcers associated with Helicobacter pylori (in combination with antibiotic therapy either clarithromycin or clarithromycin and amoxicillin) in children:
15 to 30 kg: 10 mg twice daily
Greater than 30 kg: 20 mg twice daily

Comment: The safety and efficacy of omeprazole use in patients less than 1 year of age and for pediatric uses other than the treatment of GERD and maintenance of healing of erosive esophagitis has not been established.

See also: Dosage Information (in more detail)

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking omeprazole?

Diarrhea may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.

Omeprazole side effects

Get emergency medical help if you have signs of an allergic reaction to omeprazole: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using omeprazole and call your doctor at once if you have:

  • severe stomach pain, diarrhea that is watery or bloody;

  • a rash or joint pain;

  • new or unusual pain in your wrist, thigh, hip, or back;

  • seizure (convulsions);

  • kidney problemsurinating more or less than usual, blood in your urine, swelling, rapid weight gain; or

  • symptoms of low magnesiumdrowsiness, confusion, feeling irritable, fast heartbeats, tremors, twitching, muscle cramps, numbness, tingling, or seizure.

Common omeprazole side effects may include:

  • stomach pain, gas;

  • nausea, vomiting, diarrhea; or

  • headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect omeprazole?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Ask a doctor or pharmacist before using omeprazole with any other medications, especially:

This list is not complete and many other drugs may affect omeprazole. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use omeprazole only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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