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Overview: Clarithromycin is an antibiotic that is used for infections caused by certain bacteria. It works by stopping certain types of bacteria from making proteins they need to grow and multiply. Common side effects include stomach pain, diarrhea, nausea, or vomiting. Serious side effects may include severe diarrhea, allergic reactions, or skin reactions. Clarithromycin is available as a liquid or tablet that you take by mouth.

Uses

What is clarithromycin used for?

Clarithromycin is an antibiotic that is commonly used for infections caused by certain bacteria.

Clarithromycin may also be used for other conditions as determined by your healthcare provider.

Clarithromycin may not be appropriate for all infections. Some bacteria may have developed resistance to clarithromycin, which will make it not work as well. 

Clarithromycin only treats certain infections caused by bacteria. It will not work for infections caused by viruses, such as the common cold, the flu, or coronavirus. It also will not work for any other infections that are not caused by bacteria. Taking clarithromycin or any other antibiotic when it is not needed may cause the antibiotic to not work for bacterial infections in the future.

How does clarithromycin work (mechanism of action)?

Clarithromycin stops certain types of bacteria from making proteins they need to grow and multiply.

How is clarithromycin supplied (dosage forms)?

Brands and other names

  • Biaxin
  • Biaxin XL

Dosage forms and strengths

  • 125 mg/5 mL, 250 mg/5 mL for oral suspension
  • 250 mg, 500 mg oral tablets
  • 500 mg extended-release oral tablets

How should I store clarithromycin?

Oral Tablet. Clarithromycin oral tablets should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). They can be exposed to temperatures between 59 F to 86 F (15 C to 30 C), for shorter periods of time, such as when transporting them. Store in a cool, dry place, in a tightly closed container. Protect from light.

Oral Liquid. Clarithromycin oral liquid should be stored at room temperature, between 59 F to 86 F (15 C to 30 C), and used within 14 days. You should not refrigerate or freeze it. Safely throw away any unused liquid after the full treatment is finished.

Side Effects

What are the most common side effects of clarithromycin?

The most common side effects of clarithromycin are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Stomach pain
  • Diarrhea
  • Nausea or vomiting
  • Change in how things taste

There may be other side effects of clarithromycin that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of clarithromycin?

While less common, the most serious side effects of clarithromycin are described below, along with what to do if they happen.

Severe Allergic Reactions. Clarithromycin can cause allergic reactions, including a specific type of allergic reaction called DRESS. DRESS stands for Drug Reaction with Eosinophilia and Systemic Symptoms. It is also sometimes called multiorgan hypersensitivity. This is a reaction that can affect multiple parts of the body, including your liver, kidneys, and heart. Stop taking the medicine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain
  • Dark colored urine
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Severe Skin Reactions. Clarithromycin can cause severe skin reactions, called Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP), which can lead to death if not treated. If you develop a rash, stop clarithromycin and call your healthcare provider right away. Get emergency help if you have any of the following symptoms of SJS, TEN, or AGEP.

  • Painful red or purple skin that looks burned and peels off
  • Red skin covered with fluid-filled bumps (pustules)
  • Flat red rash or blisters on your skin, mouth, nose, and genitals
  • Red, painful, watery eyes

Heart Rhythm Changes. Clarithromycin may cause a rare, dangerous heart rhythm problem called QT prolongation and torsade de pointes. Some people have a higher risk of this, including people who are older, have other people in their family who have had these conditions, have low potassium or magnesium levels, or who take other medicines that can prolong the QT interval. Tell your healthcare provider right away if you faint or have changes in your heart rate or rhythm, such as a fast or skipping heartbeat.

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking clarithromycin. Call your healthcare provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Antibiotic-associated Diarrhea. An overgrowth of germs called Clostridioides difficile, or “C. diff,” can happen in your gut with many types of antibiotics, including clarithromycin. This can cause a condition known as antibiotic-associated diarrhea and can happen even up to two months after stopping the antibiotic. Call your healthcare provider right away if you have any of the following symptoms of this condition.

  • Watery diarrhea
  • Diarrhea that does not go away
  • Blood in your stool (poop)
  • Severe stomach cramps
  • Fever that starts after you start or finish the medicine

Warnings & Precautions

Who should not use clarithromycin?

Allergies to Ingredients. People who are allergic to any of the following should not take clarithromycin.

  • Biaxin
  • Clarithromycin
  • Any other medicine known as a macrolide antibiotic
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific clarithromycin products they stock.

Drug Interactions. Clarithromycin should not be taken while you are using certain other medicines. Before taking clarithromycin, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Heart Rhythm Changes. Clarithromycin may cause a rare, dangerous heart rhythm problem called QT prolongation and torsade de pointes. If you have ever had either of these conditions, you should not take clarithromycin. 

Liver Damage from Clarithromycin. In rare cases, clarithromycin can cause liver damage. If this has happened to you in the past, you should not take clarithromycin again.

What should I know about clarithromycin before using it?

Do not take clarithromycin unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share clarithromycin with other people, even if they have the same condition as you. It may harm them.

Keep clarithromycin out of the reach of children.

Do not cut, crush, or chew clarithromycin extended-release tablets. Each extended-release tablet should be swallowed whole and taken with food. 

Clarithromycin liquid must be shaken well before use. Use an accurate measuring device to measure each dose. A household spoon is not an accurate measuring device and may cause you to take the wrong dose. Ask your pharmacist to recommend an appropriate measuring device. The bottle of liquid may contain more medicine than you need to complete your treatment. Once you or your child have taken clarithromycin liquid for the number of days prescribed by your healthcare provider, safely throw away any remaining medicine.

Clarithromycin can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how clarithromycin affects you.

People who are over the age of 65 can be at greater risk for some side effects from clarithromycin. Talk to your healthcare provider about your risks if you are in this age group.

What should I tell my healthcare provider before using clarithromycin?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if clarithromycin is right for you.

In particular, make sure that you discuss any of the following.

Heart Rhythm Problems. Tell your healthcare provider if you or anyone in your family has a history of heart attack or an irregular heartbeat (arrhythmia), especially a condition called “QT prolongation” or “long QT syndrome.”

Myasthenia Gravis. Clarithromycin may worsen the symptoms of a condition called myasthenia gravis. Tell your healthcare provider if you have this condition. 

Other Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

Pregnancy. Clarithromycin may cause harm to an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. If you become pregnant, contact your healthcare provider right away. 

Breastfeeding. Clarithromycin passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take clarithromycin while breastfeeding.

Interactions

Does clarithromycin interact with foods or drinks?

There are no known interactions between clarithromycin and foods or drinks. One specific form of clarithromycin, the extended-release tablets, should be taken with food. All other forms of clarithromycin may be taken with or without food.

It is unknown if drinking alcohol will affect clarithromycin, but heavy drinking can slow your immune response and make it harder for your body to fight infection.

Does clarithromycin interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking clarithromycin.

  • A benzodiazepine, such as clonazepam (Klonopin), diazepam (Valium and others), or lorazepam (Ativan and others), which is a medicine used for anxiety, muscle spasms, or seizures
  • A blood thinner, which is a medicine used to treat or prevent blood clots
  • A medicine for diabetes
  • A medicine used to control your heart rate or rhythm (antiarrhythmic)
  • A protease inhibitor, such as ritonavir (Norvir) or atazanavir (Reyataz), which is a medicine commonly used to treat HIV
  • A statin, such as atorvastatin (Lipitor and others) or rosuvastatin (Crestor), which is a medicine to lower cholesterol
  • An ergot, such as ergotamine (Ergomar) or dihydroergotamine (Migranal or Trudhesa), which is a medicine used to treat migraine
  • Colchicine, which is a medicine commonly used for gout
  • Lomitapide (Juxtapid, Lojuxta), which is a medicine to lower cholesterol
  • Quetiapine (Seroquel) or lurasidone (Latuda), which is a medicine used to treat certain mental health problems
  • Medicines that can cause QT prolongation, which is a potentially dangerous heart rhythm problem
  • Pimozide, which is a medicine for Tourette syndrome

Many other medicines may alter the blood levels of clarithromycin, and vice versa. Tell your healthcare provider about all medicines that you take or have recently taken.

This may not be a complete list of medicines that can interact with clarithromycin. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much clarithromycin?

If you or someone else has used too much clarithromycin, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of clarithromycin?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.

It is important to complete your prescribed course of clarithromycin, even if your symptoms get better or go away. This will reduce the risk that future infections are resistant to clarithromycin or other similar medicines.