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Amoxicillin

Brand names: Amoxil

Amoxicillin is a penicillin antibiotic that treats many bacterial infections, such as ear infections, strep throat, and sinus infections.

Brand namesAmoxil
Type of medicinePenicillin 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 kills bacteria. It does not work on viruses like colds or flu.

Amoxicillin-clavulanate (Augmentin) is a combination that works against more bacteria.

What it's used for

  • Ear, nose, and throat infections
  • Strep throat
  • Sinus infections and pneumonia
  • Urinary tract and skin infections
  • H. pylori stomach infection (with other medicines)
  • Early Lyme disease

How to take it

  • Take it with or without food, spaced evenly through the day.
  • Finish the full course even if you feel better.
  • Shake the liquid well and use the measuring device that comes with it. Keep it in the fridge if the label says so.

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

  • Diarrhea
  • Nausea
  • A mild rash
Call 911Hives, swelling of the face or throat, or trouble breathing
Call 911Blistering or peeling skin
Call your provider todaySevere watery or bloody diarrhea, even weeks after finishing (possible C. diff)
Call your provider todayA rash with fever, joint pain, or swollen glands

Warnings

  • Don't take it if you're allergic to penicillin. Tell your provider about any past reaction to antibiotics.
  • A rash is common in people with mono who take it.

Other medicines, foods, and alcohol

  • Allopurinol increases the chance of a rash.
  • It can increase the effect of warfarin.
  • Probenecid raises amoxicillin levels.

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

Pregnancy and breastfeeding

Amoxicillin is commonly used in pregnancy and breastfeeding when an antibiotic is needed.

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.