Overview: Amoxicillin is an antibiotic that is used for infections caused by certain bacteria. It kills certain bacteria by preventing them from being able to create their cell wall. Common side effects include diarrhea, rash, nausea, or vomiting. Serious side effects are rare but may include severe diarrhea, allergic reactions, or skin reactions. Amoxicillin is available in several dosage forms that you take by mouth, including a capsule, liquid, or tablet.

Uses

What is amoxicillin used for?

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

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

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

Amoxicillin 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 amoxicillin or any other antibiotic when it is not needed may cause the antibiotic to not work for bacterial infections in the future.

How does amoxicillin work (mechanism of action)?

Amoxicillin kills certain bacteria by preventing them from being able to create their cell wall.

How is amoxicillin supplied (dosage forms)?

Brands and other names

  • Amoxil
  • Larotid
  • Trimox

Dosage forms and strengths

  • 125 mg and 250 mg chewable tablets
  • 250 mg and 500 mg oral capsules
  • 125 mg/5 mL, 200 mg/5 mL, 250 mg/5 mL, and 400 mg/5 mL for oral suspension
  • 500 mg and 875 mg oral tablets

How should I store amoxicillin?

Oral Tablet and Oral Capsule. Amoxicillin tablets and capsules 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.

Oral Liquid. Amoxicillin liquid will be mixed for you by the pharmacy. Once it has been mixed, it must be used within 14 days. The mixed liquid should be stored at room temperature or in the refrigerator, between 36 F to 77 F (2 C to 25 C). Throw it away after 14 days.

Side Effects

What are the most common side effects of amoxicillin?

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

  • Diarrhea (see below)
  • Skin rash, which can be mild to severe (see below)
  • Nausea and vomiting

There may be other side effects of amoxicillin 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 amoxicillin?

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

Severe Allergic Reactions. Amoxicillin 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. Amoxicillin 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 amoxicillin 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

Antibiotic-associated Diarrhea. An overgrowth of germs called Clostridioides difficile, or “C. diff,” can happen in your gut with many types of antibiotics, including amoxicillin. 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

Drug-induced Enterocolitis Syndrome (DIES). Amoxicillin may cause a rare reaction in the gastrointestinal (GI) tract called drug-induced enterocolitis syndrome (DIES). This rare reaction usually occurs within a day of taking amoxicillin. Stop taking amoxicillin and call your healthcare provider right away if you have any of the following symptoms within 24 hours of taking this medicine. 

  • Severe vomiting that happens within a couple hours of taking the medicine
  • Severe diarrhea
  • Extreme tiredness or weakness
  • Unusually pale skin
  • Low blood pressure
  • Dizziness or lightheadedness
  • Confusion
  • Unsteadiness

Warnings & Precautions

Who should not use amoxicillin?

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

  • Amoxicillin
  • Amoxil
  • Larotid
  • Any of the ingredients in the specific product dispensed

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

Allergies to Certain Antibiotics. Some people who have an allergy to certain other antibiotics, such as penicillin, may also be allergic to amoxicillin. Let your healthcare provider know if you have ever had a severe allergic reaction to an antibiotic.

What should I know about amoxicillin before using it?

Amoxicillin may cause an upset stomach. Taking amoxicillin with a meal may help to reduce the risk of an upset stomach.

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

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

Keep amoxicillin out of the reach of children. 

Amoxicillin liquid may be stored in the refrigerator to improve how it tastes. If it is stored in the refrigerator, take special precautions to keep it away from children who also use the refrigerator. The bottle may contain more medicine than you need to complete your treatment. Once you or your child have used the liquid for the number of days prescribed by your healthcare provider, throw away any remaining medicine.

Amoxicillin liquid must be shaken before measuring each dose. Use an accurate measuring device to measure each dose and rinse this device after each use. 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. 

What should I tell my healthcare provider before using amoxicillin?

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 amoxicillin is right for you.

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

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

  • An allergy to penicillin or any other medicines
  • Nausea, vomiting, or problems with your stomach or intestines
  • History of antibiotic-associated diarrhea
  • Kidney problems
  • Mononucleosis, also called “mono” or the kissing disease

Other Medicines and Supplements. Amoxicillin may interact with other medicines and supplements. Before taking amoxicillin, 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.

Pregnancy. It is not known if or how amoxicillin could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should take amoxicillin while you are pregnant or trying to get pregnant.

Breastfeeding. Amoxicillin 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 amoxicillin while breastfeeding.

Interactions

Does amoxicillin interact with foods or drinks?

There are no known interactions between amoxicillin and foods or drinks.

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

Does amoxicillin 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 amoxicillin.

  • A birth control pill
  • Allopurinol or probenecid, which is a medicine commonly used for gout
  • A blood thinner, such as warfarin, which is a medicine used to treat or prevent blood clots
  • A macrolide antibiotic, such as clarithromycin or erythromycin (Ery-Tab and others), which is a medicine used for bacterial infections
  • A tetracycline, such as tetracycline, doxycycline, minocycline, omadacycline (Nuzyra), or sarecycline (Seysara), which is a medicine used to treat infections or other conditions
  • Any other antibiotic, which is a medicine used for bacterial infections

This may not be a complete list of medicines that can interact with amoxicillin. 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 amoxicillin?

If you or someone else has used too much amoxicillin, 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 amoxicillin?

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 amoxicillin, even if your symptoms get better or go away. This will reduce the risk that future infections are resistant to amoxicillin or other similar medicines.