Amoxicillin and clarithromycin are antibiotic that fight bacteria in the body. Omeprazole decreases the amount of acid produced in the stomach.

Omeclamox-Pak (Omeclamox-Pak) is a combination medicine used to prevent stomach ulcer caused by infection with Helicobacter pylori (H. pylori).

Omeclamox-Pak may also be used for purposes not listed in this medication guide.

Tell your doctor about all your other medicines. Some drugs should not be used with Omeclamox-Pak.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Each dose of this combination medication contains 4 pills (3 capsules and 1 tablet). Take all 4 pills twice daily before you eat, unless your doctor tells you otherwise.

Swallow each pill whole and do not crush, chew, break, or open it.

Keep using this medicine even if your symptoms quickly improve. Skipping doses could make your infection resistant to medication. Omeclamox-Pak will not treat a viral infection (flu or a common cold).

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

Store at room temperature, away from moisture, heat, and light.

You should not use Omeclamox-Pak if you are allergic to amoxicillin (Amoxil), clarithromycin (Biaxin), or omeprazole (Prevacid), or if:

• you are allergic to azithromycin (Zithromax, Z-Pak), erythromycin, or telithromycin;

• you are allergic to albendazole or mebendazole;

• you have had a severe allergic reaction to a penicillin antibiotic, including ampicillin, Augmentin, Principen, Timentin, Trimox, and others; or

• you have had a severe allergic reaction to a cephalosporin antibiotic such as cefdinir, cefprozil, cefuroxime, cephalexin, Duricef, Omnicef, Cefzil, Keflex, Spectracef, and others.

Some drugs should not be used with Omeclamox-Pak. Taking any of the following medicines together with Omeclamox-Pak can cause a life-threatening side effect on your heart:

• ergotamine;

• dihydroergotamine; or

• pimozide.

Tell your doctor if you have ever had:

• liver disease;

• kidney disease;

• allergies;

• myasthenia gravis;

You may be more likely to have a broken bone while taking this medicine long term or more than once per day. Talk with your doctor about ways to keep your bones healthy.

May harm an unborn baby. Use birth control and tell your doctor if you become pregnant.

Amoxicillin can make birth control pills less effective. Ask your doctor about other birth control options such as an injection, implant, skin patch, vaginal ring, condom, diaphragm, cervical cap, or contraceptive sponge.

Do not breastfeed while using this medicine. If you use a breast pump during this time, throw out the milk and do not feed it to your baby.

Not approved for use by anyone younger than 18 years old.

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.

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

Antibiotic medicines can cause diarrhea. Tell your doctor if you have diarrhea that is watery or bloody.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Omeclamox-Pak may cause serious side effects. Call your doctor at once if you have:

• severe stomach pain, diarrhea that is watery or bloody (even if it occurs months after your last dose);

• fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out);

• liver problems--upper stomach pain, itching, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);

• kidney problems--nausea, loss of appetite, not feeling well, fever, rash, painful urination, pain in your side or lower back;

• new or worsening symptoms of lupus--joint pain, and a skin rash on your cheeks or arms that worsens in sunlight; or

• signs of new infection--fever, cough, tiredness, trouble breathing, sores or white patches in your mouth or throat, stomach pain, vomiting, neck pain, sensitivity to light.

Serious side effects may be more likely in older adults.

Taking Omeclamox-Pak long-term may cause you to develop stomach growths called fundic gland polyps. Talk with your doctor about this risk.

Common side effects of Omeclamox-Pak may include:

• diarrhea;

• headache; or

• unusual or unpleasant taste in your mouth.

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.

A gout medication called colchicine (Colcrys) can interact with clarithromycin and cause serious or life-threatening medical problems. You should not take colchicine during your treatment with Omeclamox-Pak, especially if you are an older adult with kidney disease.

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.

Clarithromycin can cause a serious heart problem. Your risk may be higher if you also use certain other medicines for infections, asthma, heart problems, high blood pressure, depression, mental illness, cancer, malaria, or HIV.

Tell your doctor about all your current medicines, especially:

• cilostazol;

• carbamazepine;

• probenecid;

• sildenafil (Viagra and others);

• tacrolimus;

• theophylline;

• heart rhythm medication;

• HIV/AIDS medication;

• a sedative such as alprazolam, midazolam, triazolam, Xanax, or Versed;

• "statin" cholesterol medication; or

• a blood thinner (warfarin, Coumadin, Jantoven).

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