Brand Name(s):

  • Biaxin®Filmtab®
  • Biaxin®Granules
  • Biaxin®XL Filmtab
  • Biaxin®XL Pac

WHY is this medicine prescribed?

Clarithromycin is used to treat certain infections caused by bacteria, such as pneumonia (a lung infection), bronchitis (infection of the tubes leading to the lungs), and infections of the ears, sinuses, skin, and throat. It also is used to treat and prevent disseminated Mycobacterium avium complex (MAC) infection [a type of lung infection that often affects people with human immunodeficiency virus (HIV)]. It is used in combination with other medications to eliminateH. pylori, a bacteria that causes ulcers. Clarithromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria. Antibiotics will not work for colds, flu, or other viral infections.

HOW should this medicine be used?

Clarithromycin comes as a tablet, an extended-release (long-acting) tablet, and a suspension (liquid) to take by mouth. The regular tablet and liquid are usually taken with or without food every 12 hours (twice a day) for 7-14 days. The long-acting tablet is usually taken with food every 24 hours (once a day) for 7-14 days. Take clarithromycin at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take clarithromycin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Shake the liquid well before each use to mix the medication evenly.

The tablets should be taken with a full glass of water. Swallow the long-acting tablets whole; do not split, chew, or crush them.

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

Are there OTHER USES for this medicine?

Clarithromycin also is used sometimes to treat other types of infections including Lyme disease (an infection that may develop after a person is bitten by a tick), crypotosporidiosis (an infection that causes diarrhea), cat scratch disease (an infection that may develop after a person is bitten or scratched by a cat), Legionnaires' disease (a type of lung infection), and pertussis (whooping cough; a serious infection that can cause severe coughing). It is also sometimes used to prevent heart infection in patients having dental or other procedures. Talk to your doctor about the possible risks of using this medication for your condition.

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

What SPECIAL PRECAUTIONS should I follow?

Before taking clarithromycin,

  • tell your doctor and pharmacist if you are allergic to clarithromycin, azithromycin (Zithromax), dirithromycin (Dynabac) (not available in the U.S.), erythromycin (E.E.S., E-Mycin, Erythrocin), telithromycin (Ketek), or any other medications
  • tell your doctor if you are taking astemizole (Hismanal) (not available in the U.S.), cisapride (Propulsid), dihydroergotamine (DHE 45, Migranal), ergotamine (Ergomar, in Cafergot, in Migergot), pimozide (Orap), or terfenadine (Seldane) (not available in the U.S.). Your doctor may tell you not to take clarithromycin if you are taking one or more of these medications.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin); alfentanil (Alfenta); alprazolam (Xanax); bromocriptine (Parlodel); carbamazepine (Tegretol); cholesterol-lowering medications such as lovastatin (Mevacor) and simvastatin (Zocor); cilostazol (Pletal); colchicine; cyclosporine (Neoral, Sandimmune); darifenacin (Enablex); digoxin (Lanoxin); erlotinib (Tarceva); eszopiclone (Lunesta); fluconazole (Diflucan); certain medications for HIV such as nelfinavir (Viracept), ritonavir (Norvir), and ziodvudine (AZT, Retrovir); certain medications for irregular heartbeat such as disopyramide (Norpace) and quinidine; methylprednisolone (Medrol), midazolam (Versed); omeprazole (Prilosec); phenytoin (Dilantin); ranitidine (Zantac); rifabutin (Mycobutin); rifampin (Rifadin, Rimactane); sildenafil (Viagra), tacrolimus (Prograf); theophylline (Theo-Dur); triazolam (Halcion); valproate (Depacon) and valproic acid (Depakote). Many other medications may also interact with clarithromycin, so tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had kidney or liver disease .
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking clarithromycin, call your doctor.

What SPECIAL DIETARY instructions should I follow?

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

What should I do IF I FORGET to take a dose?

Take the missed dose 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 medicine cause?

Clarithromycin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • diarrhea
  • nausea
  • heartburn
  • abnormal taste
  • stomach pain
  • headache

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

  • rash
  • hives
  • itching
  • swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
  • difficulty breathing or swallowing
  • hoarseness
  • blisters or red splotches on skin
  • fever
  • yellowing of the skin or eyes
  • unusual bruising or bleeding
  • pain in the upper right part of the stomach
  • lack of energy
  • flu-like symptoms
  • fast, pounding, or irregular heartbeat

Clarithromycin 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 [at Web Site] 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 the tablets at room temperature and away from excess heat and moisture (not in the bathroom). Keep away from light. Throw away any medication that is outdated or no longer needed. Do not refrigerate the oral solution. Keep it at room temperature and away from excess heat and moisture. Throw away any unused oral solution after 14 days. Talk to your pharmacist about the proper disposal of your medication.

What should I do in case of OVERDOSE?

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Symptoms of overdose may include:

  • stomach pain
  • nausea
  • vomiting
  • diarrhea

What OTHER INFORMATION should I know?

Keep all appointments with your doctor.

The extended-release tablet does not dissolve in the stomach after swallowing. It slowly releases the medicine as it passes through your digestive system. You may notice the tablet coating in the stool. This is normal and does not mean that you did not get the full dose of medication.

Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of infection after you finish the clarithromycin, call your doctor.

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.

AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Last Reviewed: September 1, 2010.