Clarithromycin (By mouth)


Clarithromycin (kla-rith-roe-MYE-sin)

This medicine is a macrolide antibiotic that treats and prevents infections, and also treats duodenal ulcers caused by H pylori.

Brand Name(s)

Biaxin, Biaxin Filmtab, Biaxin XL, Omeclamox-Pak, Prevpac, Triple Therapy

When This Medicine Should Not Be Used

How to Use This Medicine

Liquid, Tablet, Long Acting Tablet

  • Take your medicine as directed. Take it at the same time each day.
  • Take all of the medicine in your prescription to clear up your infection, even if you feel better after the first few doses.
  • If you take the extended-release tablet, part of the tablet may pass into your stools. This is normal and is nothing to worry about.
  • Extended-release tablets: Biaxin® XL extended-release tablets should be taken with food. Swallow the extended-release tablet whole. Do not break, crush, or chew it.
  • Tablets: These may be taken with or without food. Swallow the tablet whole. Do not break, crush, or chew it.
  • Liquid (suspension): This may also be taken with or without food. Shake the bottle of medicine well right before you measure each dose.Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.
  • Missed doseTake a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not refrigerate or freeze the oral liquid. Throw away any leftover oral liquid 14 days after you fill the prescription.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Do not use this medicine if you also use cisapride, lovastatin, pimozide, simvastatin, or certain ergot medicines. Do use this medicine together with colchicine if you have kidney or liver disease, or with ranitidine bismuth citrate if you have kidney disease or a history of porphyria.
  • There are many other drugs that can interact with clarithromycin. Make sure your doctor knows about all other medicines you are using.
  • Some foods and medicines can affect how clarithromycin works. Tell your doctor if you also use St John's wort, bromocriptine, cilostazol, colchicine, cyclosporine, digoxin, itraconazole, methylprednisolone, omeprazole, rifabutin, rifampicin, rifapentine, tacrolimus, theophylline, tolterodine, vinblastine. Tell your doctor if you also use a calcium channel blocker (lowers blood pressure), medicine for heart rhythm problems (such as quinidine, procainamide, dofetilide, amiodarone, sotalol), medicine to lower cholesterol, medicine to treat diabetes, medicine to treat HIV or AIDS, medicine for seizures, medicine to treat impotence, a benzodiazepine (tranquilizer), or warfarin or another blood thinner.
  • If you also take zidovudine, clarithromycin and zidovudine should be taken at least 2 hours apart.

Warnings While Using This Medicine

  • Tell your doctor if you are pregnant or breastfeeding, or if you have a history of liver problems caused by clarithromycin or a history of heart rhythm problems. Tell your doctor if you have kidney disease, liver disease, diabetes, myasthenia gravis, or a history of porphyria.
  • This medicine may cause the following problems:
    • Changes in heart rhythm
    • Liver problems
    • Severe diarrhea
  • This medicine can cause diarrhea. Call your doctor if the diarrhea becomes severe, does not stop, or is bloody. Do not take any medicine to stop diarrhea until you have talked to your doctor. Diarrhea can occur 2 months or more after you stop taking this medicine. Diarrhea may occur 2 months or more after you stop using this medicine.
  • Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Blistering, peeling, or red skin rash
  • Dark urine, pale stools, nausea, vomiting, loss of appetite, stomach pain, yellow skin or eyes
  • Fast, slow, pounding, or uneven heartbeat
  • Severe nausea, vomiting, upset stomach, abdominal pain
  • Severe diarrhea that does not stop

If you notice other side effects that you think are caused by this medicine, tell your doctor

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

Version Info

  • Last reviewed on 8/4/2014

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