Clarithromycin: Uses & Side Effects

Clarithromycin is a macrolide antibiotic that fights bacteria in your body.

Clarithromycin is used to treat many different types of bacterial infections affecting the skin and respiratory system.

Clarithromycin is also used together with other medicines to treat stomach ulcers caused by Helicobacter pylori.


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 had jaundice or liver problems caused by taking clarithromycin; or
  • you have liver or kidney disease and you also take a medicine called colchicine.

Some medicines can cause unwanted or dangerous effects when used with clarithromycin. 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 this medicine is safe for you, tell your doctor if you have ever had:

  • heart problems;
  • long QT syndrome (in you or a family member);
  • coronary artery disease (clogged arteries);
  • myasthenia gravis;
  • liver disease;
  • kidney disease;
  • diabetes; or
  • an electrolyte imbalance (such as low levels of potassium or magnesium in your blood).

Clarithromycin may harm an unborn baby. Use effective birth control to prevent pregnancy while you are using this medicine. Tell your doctor if you become pregnant.

In animal studies, clarithromycin caused birth defects. However, it is not known whether these effects would occur in humans. Ask your doctor about your risk.


Side effects

Call your doctor at once if you have:

  • severe stomach pain, diarrhea that is watery or bloody;
  • fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out);
  • confusion, spinning sensation;
  • liver problems – loss of appetite, upper stomach pain, tiredness, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or
  • kidney problems – little or no urination, swelling in your feet or ankles, feeling tired or short of breath.

If you’ve ever had heart problems, clarithromycin may cause a heart attack or stroke years after you’ve taken this medicine. Seek medical attention right away if you have chest pain spreading to your jaw or shoulder, trouble breathing, slurred speech, or sudden numbness or weakness on one side of your body.

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

Common clarithromycin side effects may include:

  • stomach pain, nausea, vomiting;
  • diarrhea; or
  • unusual or unpleasant taste in your mouth.


Keyword: clarithromycin.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.