Health Library

Clarithromycin (By mouth)

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

Treats and prevents infections. Also treats duodenal ulcers caused by H pylori. This medicine is a macrolide antibiotic.

Brand Name(s):

Biaxin, Biaxin Filmtab, Biaxin XL, Prevpac

When This Medicine Should Not Be Used:

How to Use This Medicine:

Liquid, Tablet, Long Acting Tablet

• Your doctor will tell you how much medicine to use. Do not use more than directed.
• 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: These 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.
• Oral liquid: This may also be taken with or without food. Shake the bottle well before you measure the medicine. Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.
• Missed dose: Take 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 are also using cisapride, lomitapide, lovastatin, pimozide, simvastatin, or 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. Tell your doctor if you are also using any of the following:
  • Alfentanil, alprazolam, atorvastatin, bromocriptine, cilostazol, colchicine, cyclosporine, digoxin, itraconazole, midazolam, methylprednisolone, omeprazole, phenobarbital, phenytoin, pravastatin, quetiapine, rifabutin, sildenafil, tacrolimus, tadalafil, theophylline, tolterodine, triazolam, valproate, vardenafil, vinblastine, or St John's wort
  • Blood pressure medicine
  • Blood thinner (including warfarin)
  • Insulin or diabetes medicine taken by mouth
  • Medicine for heart rhythm problems (including amiodarone, disopyramide, dofetilide, procainamide, quinidine, sotalol)
  • Medicine to treat HIV or AIDS
  • Seizure medicine (including carbamazepine)
• 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 breastfeeding, or if you have kidney disease, liver disease, heart disease, diabetes, myasthenia gravis, or a history of porphyria. Tell your doctor if anyone in your family has heart rhythm problems.
• This medicine may cause the following problems:
  • Serious skin reactions
  • Changes in heart rhythm (including QT prolongation)
  • Liver problems
• This medicine may make you dizzy or confused. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.
• 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. It may occur 2 months or more after you stop using this medicine.
• Call your doctor if your symptoms do not improve or if they get worse.
• 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, red skin rash
• Dark urine, pale stools, loss of appetite, yellow skin or eyes
• Fast, slow, pounding, or uneven heartbeat, chest pain
• Severe diarrhea that may contain blood
• Severe nausea, vomiting, stomach pain

If you notice these less serious side effects, talk with your doctor:

• Change in taste
• Mild diarrhea, nausea, vomiting, stomach pain

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

Last Updated: 9/6/2024