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Omeprazole, Clarithromycin, and Amoxicillin

pronounced as (oh me' pray zol) (kla rith' roe mye sin) (a mox i sil' in)

Why is this medication prescribed?

Omeprazole, clarithromycin, and amoxicillin are used to treat and prevent the return of ulcers (sores in the lining of the stomach or intestine) caused by a certain type of bacteria (H. pylori). Omeprazole is in a class of medications called proton pump inhibitors. Clarithromycin and amoxicillin are in a class of medications called antibiotics. Omeprazole works by decreasing the amount of acid made in the stomach. Clarithromycin and amoxicillin work by stopping the growth of the bacteria that may cause ulcers.

Antibiotics will not work for colds, flu, and other viral infections. Taking antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.

How should this medicine be used?

Omeprazole comes as a delayed-release (releases the medication in the intestine to prevent break-down of the medication by stomach acids) capsule, clarithromycin comes as a tablet, and amoxicillin comes as a capsule, all to be taken by mouth. These medications are usually taken before a meal twice a day, in the morning and in the evening. To help you take the right number of capsules and tablets at each dose, the medication is packaged in dosing cards. Each dosing card contains all of the medication needed for both daily doses. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take the medication exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets and capsules whole; do not split, chew, or crush them.

Take omeprazole, clarithromycin, and amoxicillin until you finish the prescription, even if you feel better. If you stop taking antibiotics too soon your infection may not be completely treated and the bacteria may become resistant to antibiotics.

If your condition does not improve or gets worse, call your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Other uses for this medicine

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

What special precautions should I follow?

Before taking omeprazole, clarithromycin, and amoxicillin,

  • tell your doctor and pharmacist if you are allergic to omeprazole, dexlansoprazole (Dexilant), esomeprazole (Nexium), lansoprazole (Prevacid), pantoprazole (Protonix), or rabeprazole (Aciphex); clarithromycin; amoxicillin (Amoxil, Larotid); penicillin; other antibiotics such as azithromycin (Zithromax), or erythromycin (E.E.S. Ery-Tab, others); cephalosporins such as cefaclor, cefadroxil, cefuroxime and cephalexin; any other medications; or any of the ingredients in amoxicillin tablets, clarithromycin capsules, or omeprazole capsules. Ask your pharmacist for a list of the ingredients.
  • Some medications should not be taken with omeprazole, clarithromycin, and amoxicillin. Make sure you have discussed any medications you are currently taking or plan to take before starting omeprazole, clarithromycin, and amoxicillin with your doctor and pharmacist. Before starting, stopping or changing any medications while taking omeprazole, clarithromycin, and amoxicillin, get the advice of your healthcare provider.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • The following nonprescription or herbal products may interact with omeprazole, clarithromycin, and amoxicillin: St. John's Wort. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking omeprazole, clarithromycin, and amoxicillin. Do not start any of these medications while taking omeprazole, clarithromycin, and amoxicillin without discussing with your healthcare provider.
  • tell your doctor if you have or have ever had a QT prolongation (an irregular heart rhythm that can lead to fainting, loss of consciousness, seizures, or sudden death) or an irregular heartbeat; asthma, allergies, hives, hay fever, lupus (a condition in which the immune system attacks many tissues and organs including the skin, joints, blood, and kidneys), myasthenia gravis (a disease that causes muscle weakness), or kidney or liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant or are breastfeeding. If you become pregnant while taking these medications, call your doctor.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking omeprazole, clarithromycin, and amoxicillin.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

Take the missed dose (one omeprazole capsule, one clarithromycin tablet, and two amoxicillin capsules) as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Omeprazole, clarithromycin, and amoxicillin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • diarrhea
  • stomach pain or cramps
  • vomiting
  • nausea
  • change in ability to taste food
  • headache
  • dizziness

Some side effects can be serious. If you experience any of these symptoms, stop taking omeprazole, clarithromycin, and amoxicillin and call your doctor immediately or get emergency medical treatment:

  • blistering or peeling skin
  • rash; hives; itching; swelling of the lips, face, or tongue; shortness of breath; difficulty breathing or swallowing
  • watery or bloody diarrhea with or without stomach pain or fever that occurs during your treatment or for up to 2 months afterward
  • new or worsening joint pain; rash on cheeks or arms that is sensitive to sunlight
  • increased or decreased urination, blood in urine, fatigue, nausea, loss of appetite, fever, or rash`
  • yellow eyes or skin, loss of appetite, dark urine; itching, abdominal pain, unexplained bruising or bleeding, or loss of appetite
  • muscle weakness such as difficulty chewing, talking, or performing daily activities
  • double vision

Omeprazole, clarithromycin, and amoxicillin may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from light, excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( for more information if you do not have access to a take-back program.

In case of emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

  • confusion
  • drowsiness
  • blurred vision
  • fast or pounding heartbeat
  • headache
  • sweating flushing (feeling of warmth)
  • dry mouth
  • stomach pain
  • nausea
  • vomiting
  • diarrhea
  • decreased urination

What other information should I know?

Keep all appointments with your doctor and the laboratory.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking omeprazole, clarithromycin, and amoxicillin.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

  • Omeclamox-Pak®
Last Revised - 02/15/2024