clarithromycin

You should not use this medicine if you have a life-threatening heart rhythm disorder, a history of Long QT syndrome, if you have ever had jaundice or liver problems caused by taking clarithromycin, or if you have liver or kidney disease and are also taking colchicine.

Many other drugs can interact with clarithromycin. There are certain medicines that can cause life-threatening drug interactions with clarithromycin, and should not be used at the same time. Tell each of your healthcare providers about all medicines you use now, and any medicine you start or stop using.

Take this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Clarithromycin will not treat a viral infection such as the common cold or flu.

Before taking this medicine

You should not use this medicine if you are allergic to clarithromycin or similar medicines such as azithromycin (Zithromax, Z-Pak, Zmax), erythromycin, or telithromycin, or if you have:

• a life-threatening heart rhythm disorder;

• a history of Long QT syndrome;

• if you have ever had jaundice or liver problems caused by taking clarithromycin; or

• if you have liver or kidney disease and you are also taking colchicine.

There are certain medicines that can cause life-threatening drug interactions with clarithromycin, and should not be used at the same time. Your doctor may need to change your treatment plan if you use any of the following drugs:

• cisapride;

• pimozide;

• lovastatin or simvastatin; or

• ergotamine or dihydroergotamine.

To make sure clarithromycin is safe for you, tell your doctor if you have:

• liver disease;

• kidney disease;

• myasthenia gravis;

• porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system);

• an electrolyte imbalance (such as low levels of potassium or magnesium in your blood);

• a family history of Long QT syndrome; or

• if you take certain heart rhythm medicine--amiodarone, disopyramide, dofetilide, flecainide, dronedarone, ibutilide, mexiletine, procainamide, propafenone, quinidine, or sotalol.

FDA pregnancy category C. It is not known whether clarithromycin will harm an unborn baby. Tell your doctor if you are pregnant or if you become pregnant while using this medicine.

See also: Pregnancy and breastfeeding warnings (in more detail)

In animal studies, clarithromycin caused birth defects. However, very high doses are used in animal studies. It is not known whether these effects would occur in people using regular doses. Ask your doctor about your risk.

Clarithromycin can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Do not give this medicine to a child younger than 6 months of age.

How should I take clarithromycin?

Take clarithromycin exactly as prescribed by your doctor. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

You may take the tablets and oral suspension (liquid) with or without food.

Clarithromycin extended-release tablets (Biaxin XL) should be taken with food.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

Shake the oral suspension (liquid) well just before you measure a dose. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Use this medicine for the full prescribed length of time. Clarithromycin is usually given for up to 7 to 14 days. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Clarithromycin will not treat a viral infection such as the flu or a common cold.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

Do not keep the oral liquid in a refrigerator. Throw away any liquid that has not been used within 14 days.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

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

Overdose symptoms may include severe stomach pain, nausea, vomiting, or diarrhea.

What should I avoid while taking clarithromycin?

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, stop taking this medicine and call your doctor. Do not use anti-diarrhea medicine unless your doctor tells you to.

Clarithromycin side effects

Get emergency medical help if you have any of these signs of an allergic reaction to clarithromycin: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• headache with chest pain and severe dizziness, fast or pounding heartbeats, shortness of breath, fainting;

• diarrhea that is watery or bloody;

• fever, swollen glands, body aches, flu symptoms, new or worsening cough;

• skin rash, easy bruising or bleeding, severe tingling, numbness, pain, muscle weakness;

• problems with your hearing;

• signs of a kidney problem--little or no urinating; painful or difficult urination; swelling in your feet or ankles; feeling tired or short of breath; or

• severe skin reaction--fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Older adults may be more likely to have heart rhythm side effects, including a life-threatening fast heart rate.

Clarithromycin may also cause severe liver symptoms. Stop taking clarithromycin and call your doctor at once if you have any of these liver symptoms:

• itching, tired feeling;

• nausea, upper stomach pain, loss of appetite;

• dark urine, clay colored stools; or

• jaundice (yellowing of the skin or eyes).

Common clarithromycin side effects may include:

• stomach pain, indigestion, gas;

• vomiting, mild diarrhea;

• unusual or unpleasant taste in your mouth;

• headache, sleep problems (insomnia);

• mild itching or rash; or

• vaginal itching or discharge.

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.

See also: Side effects (in more detail)

What other drugs will affect clarithromycin?

Many drugs can interact with clarithromycin. Not all possible interactions are listed here. Tell your doctor about all your medications and any you start or stop using during treatment, especially:

• saquinavir;

• carbamazepine;

• theophylline;

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

• sildenafil (Viagra) and other erectile dysfunction medicines;

• ergot medicine--ergonovine, methylergonovine; or

• heart rhythm medication such as amiodarone, disopyramide, dofetilide, procainamide, quinidine, or sotalol.

This list is not complete and many other drugs can interact with clarithromycin. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Give a list of all your medicines to any healthcare provider who treats you.