Amoxicillin: Uses & Side Effects

Amoxicillin is a penicillin antibiotic that fights bacteria.

Amoxicillin is used to treat many different types of infection caused by bacteria, such as tonsillitis, bronchitis, pneumonia, gonorrhea, and infections of the ear, nose, throat, skin, or urinary tract.

Amoxicillin is also sometimes used together with another antibiotic called clarithromycin (Biaxin) to treat stomach ulcers caused by Helicobacter pylori infection. This combination is sometimes used with a stomach acid reducer called lansoprazole (Prevacid).


Before taking this medicine

You should not use amoxicillin if you are allergic to any penicillin antibiotic, such as ampicillin, dicloxacillin, oxacillin, penicillin, or ticarcillin.

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

  • asthma;
  • liver or kidney disease;
  • mononucleosis (also called “mono”);
  • a history of diarrhea caused by taking antibiotics; or
  • food or drug allergies (especially to a cephalosporin antibiotic such as Omnicef, Cefzil, Ceftin, Keflex, and others).

Amoxicillin is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Amoxicillin can make birth control pills less effective. Ask your doctor about using non hormonal birth control (condom, diaphragm with spermicide) to prevent pregnancy while taking this medicine.

Amoxicillin can pass into breast milk, but based on a small number of studies, it has not been shown to cause any harm to a baby. Tell your doctor if you are breast-feeding a baby.

The amoxicillin chewable tablet may contain phenylalanine. Talk to your doctor before using the chewable tablets if you have phenylketonuria (PKU).


Side effects

Call your doctor at once if you have:

  • diarrhea that is watery or bloody;
  • black, swollen or “hairy” tongue;
  • fever, swollen gums, painful mouth sores, pain when swallowing, skin sores, cold or flu symptoms, cough, trouble breathing;
  • swollen glands, rash or itching, joint pain, or general ill feeling;
  • pale or yellowed skin, yellowing of the eyes, dark colored urine, fever, confusion or weakness;
  • severe tingling, numbness, pain, muscle weakness;
  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin; 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.

Common amoxicillin side effects may include:

  • diarrhea
  • rash
  • nausea and vomiting


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* 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.