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Clarithromycin

Brand names: Biaxin (brand discontinued)

Clarithromycin is an antibiotic for some respiratory and skin infections and is part of H. pylori treatment.

Brand namesBiaxin (brand discontinued)
Type of medicineMacrolide antibiotic
Prescription?Prescription
ImportantThis page is general information, not a prescription. Don't start, stop, or change a medicine without talking to your provider or pharmacist.

Overview

It interacts with many medicines.

What it's used for

  • Pneumonia and bronchitis
  • Sinus and throat infections
  • H. pylori (with other medicines)
  • Skin infections

How to take it

  • Take it for the full course, even if you feel better.
  • Extended-release tablets are taken with food.

Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.

Side effects

Common side effects

  • Metallic taste
  • Diarrhea
  • Nausea
Call 911Fainting or a fast, irregular heartbeat
Call your provider todaySevere watery or bloody diarrhea, even weeks after finishing (possible C. diff infection)
Call your provider todayYellow skin or eyes, dark urine, or pain in the upper right belly
Call 911A blistering, peeling, or widespread red rash, especially with fever

Warnings

  • It can affect heart rhythm, especially with other medicines that do the same.
  • People with heart disease have a small long-term risk of heart problems.

Other medicines, foods, and alcohol

  • It raises levels of simvastatin, lovastatin, colchicine, and many others; some must not be combined.
  • It raises warfarin's effect.

Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.

Pregnancy and breastfeeding

Usually avoided in pregnancy.

Missed doses, overdose, and storage

If you miss a dose

Take it as soon as you remember. If it's almost time for the next dose, skip the missed one. Don't double up, and still finish the full course.

If someone takes too much

Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.

Storing it

Store at room temperature, away from heat and moisture (not in the bathroom), and out of reach of children and pets.

Conditions it's used for

Sources

Last updated 2026-11-13.