Omeprazole

Omeprazole is both an over-the-counter and a prescription medication. The over-the-counter form is used to treat heartburn. The prescription form is used to treat gastroesophageal reflux disease (GERD), certain ulcers, Zollinger-Ellison Syndrome, erosive esophagitis (EE), and infections cause by the bacteria H. pylori. This medication page refers to the prescription form of omeprazole.

Omeprazole belongs to a group of drugs called proton-pump inhibitors, which work by reducing the amount of acid made in the stomach.

This medication comes in delayed capsule form and in packets to be mixed with water to form a liquid (suspension). It is taken once or twice daily, one hour before a meal.

Common side effects of omeprazole include constipation, gas, nausea, vomiting, and headache.

Omeprazole can cause dizziness, drowsiness, and blurred vision. Do not drive or operate heavy machinery until you know how omeprazole affects you.

CYP2C19 is an enzyme in the blood that is responsible for breaking down omeprazole and other drugs in the body. Some patients have less of this protein in their bodies, affecting how much of the drug gets eliminated. Levels of CYP2C19 can vary greatly between individuals, and those having less of this protein are known as "poor metabolizers." 

CYP2C19 testing is done to determine whether you are a poor metabolizer. If you are a poor metabolizer, the levels of omeprazole in your blood can become too high. As a result you may be at an increased risk of having more side effects from omeprazole. 

Your doctor may adjust your dose of omeprazole if you are a poor metabolizer.

Omeprazole is a prescription medicine used to treat gastroesophageal reflux disease (GERD), certain ulcers, Zollinger-Ellison Syndrome, erosive esophagitis (EE), and infections cause by the bacteria H. pylori.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Omeprazole may be found in some form under the following brand names:

• Omesec

• Prilosec

• UlcerGard

• Zegerid

• Zegerid with Magnesium Hydroxide

Serious side effects have been reported with omeprazole. See the “Omeprazole Precautions” section.

Common side effects of omeprazole include:

• headache
• abdominal pain
• nausea
• diarrhea
• vomiting
• gas
• respiratory system events
• fever

This is not a complete list of omeprazole side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all of the medicines you take including prescription and non-prescription drugs, vitamins and herbal supplements. Omeprazole may affect how other medicines work, and other medicines may affect how omeprazole work. Especially tell your doctor if you take:

• atazanavir (Reyataz)
• nelfinavir (Viracept)
• saquinavir (Fortovase)
• cilostazol (Pletal)
• ketoconazole (Nizoral)
• voriconazole (Vfend)
• ampicillin (Unasyn)
• products that contain iron
• warfarin (Coumadin)
• digoxin (Lanoxin, Lanoxincaps)
• tacrolimus (Prograf)
• diazepam (Valium)
• phenytoin (Dilantin)
• disulfiram (Antabuse)
• clopidogrel (Plavix)
• St. John's wort

This is not a complete list of omeprazole drug interactions. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with omeprazole including the following:

• Serious allergic reactions. Tell your doctor if you any or all of the following symptoms of a serious allergic reaction:
  • rash
  • face swelling
  • throat tightness
  • difficulty breathing

People who are taking multiple daily doses of proton pump inhibitor medicines for a long period of time may have an increased risk of fractures of the hip, wrist or spine.

Do not take omeprazole if you:

• are allergic to omeprazole or to any of its ingredients
• are allergic to any other proton pump inhibitor

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of omeprazole there are no specific foods that you must exclude from your diet when receiving omeprazole.

Before taking omeprazole, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• have liver problems
• are pregnant or plan to become pregnant
• are breastfeeding or planning to breastfeed

Tell your doctor about all of the medicines you take including prescription and non-prescription drugs, vitamins and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X - are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Omeprazole falls into category C. There are no good studies that have been done in humans with omeprazole. In animals, pregnant animals were given this medication and had some babies born with problems. However, this medication may sometimes still help human mothers and their babies more than it might cause harm.

Tell your doctor if you are breastfeeding or planning to breastfeed.

Omeprazole has been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants from omeprazole, a choice should be made whether to stop nursing or to stop use of this medication. Determining the importance of the drug to the mother should be considered.

Take omeprazole exactly as prescribed.

This medication comes in delayed capsule form and in packets to be mixed with water to form a liquid (suspension). It is taken once or twice daily, one hour before a meal.

Swallow omeprazole capsules whole. Never chew or crush omeprazole capsules.

If you have difficulty swallowing omeprazole capsules, you may open the capsule and empty the contents into a tablespoon of applesauce. Be sure to swallow the applesauce right away. Do not store it for later use.

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take 2 doses of omeprazole at the same time.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• the condition being treated
• other medical conditions you have
• other medications you are taking
• how you respond to this medication
• your age
• your weight

The recommended adult oral dose of omeprazole for short-term treatment of active duodenal ulcer is 20 mg once daily. Most patients heal within four weeks. Some patients may require an additional 4 weeks of therapy.

Omeprazole may be used for H. pylori Eradication for the Reduction of the Risk of Duodenal Ulcer Recurrence. When used in Triple Therapy (omeprazole/clarithromycin/amoxicillin), the recommended adult oral regimen is omeprazole 20 mg plus clarithromycin 500 mg plus amoxicillin 1000 mg each given twice daily for 10 days. In patients with an ulcer present at the time of initiation of therapy, an additional 18 days of omeprazole 20 mg once daily is recommended for ulcer healing and symptom relief. When used in Dual Therapy (omeprazole/clarithromycin), the recommended adult oral regimen is omeprazole 40 mg once daily plus clarithromycin 500 mg three times daily for 14 days. In patients with an ulcer present at the time of initiation of therapy, an additional 14 days of omeprazole 20 mg once daily is recommended for ulcer healing and symptom relief.

The recommended adult oral dose of omeprazole for gastric ulcer is 40 mg once daily for 4 to 8 weeks.

The recommended adult oral dose for the treatment of patients with symptomatic GERD and no esophageal lesions is 20 mg daily for up to 4 weeks. The recommended adult oral dose for the treatment of patients with erosive esophagitis and accompanying symptoms due to GERD is 20 mg daily for 4 to 8 weeks.

The recommended adult oral dose of omeprazole for the maintenance of healing of erosive esophagitisis 20 mg daily.

The dosage of omeprazole in patients with pathological hypersecretory conditions varies with the individual patient. The recommended adult oral starting dose is 60 mg once daily. Doses should be adjusted to individual patient needs and should continue for as long as clinically indicated. Doses up to 120 mg three times daily have been administered. Daily dosages of greater than 80 mg should be administered in divided doses. Some patients with Zollinger-Ellison syndrome have been treated continuously with omeprazole for more than 5 years.

For the treatment of GERD and maintenance of healing of erosive esophagitis, the recommended daily dose for pediatric patients 1 to 16 years of age is based on weight and ranges from 5 mg to 20 mg.The safety and effectiveness of omeprazole for the treatment of GERD in patients younger than 1 year of age have not been determined.

If you take too much omeprazole, call your local Poison Control Center or seek emergency medical attention right away.

If omeprazole is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

• Store omeprazole at room temperature between 20°-25°C (68°-77°F).
• Keep the container of omeprazole closed tightly.
• Keep omeprazole and all medicines out of the reach of children.