Augmentin (amoxicillin/clavulanate potassium) is a brand-name drug that’s prescribed for some types of bacterial infection. As with other drugs, Augmentin can cause side effects, such as allergic reaction and nausea.

Augmentin belongs to the penicillin class of antibiotics. The drug is available in a generic version. Augmentin is available in these forms:

  • oral tablet
  • oral suspension (a liquid mixture)

Read on to learn about potential common, mild, and serious side effects of Augmentin. For a general overview of the drug, including details about its uses, see this article.

Augmentin can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Augmentin in clinical trials of Augmentin or Augmentin ES-600:

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Augmentin use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to the prescribing information for Augmentin or Augmentin ES-600.

Mild side effects that have been reported with Augmentin include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking Augmentin and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.

Augmentin may cause serious side effects. Serious side effects were rarely reported in clinical trials. The list below may not include all possible serious side effects of the drug. For more information, you can refer to the prescribing information for Augmentin or Augmentin ES-600.

If you develop serious side effects while taking Augmentin, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

* For more information about this side effect, see “Side effect specifics” below.

Most side effects in children are the same as those in adults. However, children may also experience tooth discoloration. Augmentin can cause yellow, gray, or brown stains on children’s teeth. Talk with your child’s dentist about tooth cleaning if they experience tooth discoloration.

As with most drugs, Augmentin can cause an allergic reaction in some people. It’s not known how often allergic reactions happened in clinical trials of Augmentin or Augmentin ES-600. Allergic reactions to Augmentin are more likely to occur if you are allergic to other penicillin or cephalosporin antibiotics or if you have other allergens.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Augmentin. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Augmentin may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Does the 875-mg/125-mg strength of Augmentin cause specific side effects?

Side effects of the 875-milligram (mg) amoxicillin/125-mg clavulanate potassium strength of Augmentin are similar to those of lower doses. In clinical trials, diarrhea was the most frequently reported side effect in people who took this strength of Augmentin. The reported rates of diarrhea were similar to those of the 500-mg amoxicillin/125-mg clavulanate potassium strength of Augmentin.

Talk with your doctor if you have questions about potential side effects with the higher dose of Augmentin.

What should I do if Augmentin is making me feel ‘weird’?

If you experience any side effects that make you feel unusual or “weird,” call your doctor right away. Common side effects of Augmentin include nausea, vomiting, and headache.

If you think your symptoms need immediate medical attention, call 911 or your local emergency number.

Should I expect ‘stomach’ pain while taking Augmentin?

Augmentin may cause abdominal pain and diarrhea, which could produce feelings of “stomach” pain. However, abdominal pain was not commonly reported in clinical trials of Augmentin.

If you experience this or other side effects that are bothersome to you, talk with your doctor.

Is constipation one of Augmentin’s side effects?

Constipation was not reported in clinical trials of Augmentin. It’s more likely you could experience diarrhea, which was a reported side effect in clinical trials.

If you have constipation while taking Augmentin, talk with your doctor.

Learn more about some of the side effects that Augmentin may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Augmentin or Augmentin ES-600.

Fatigue

Fatigue is a possible side effect of Augmentin. It’s unknown how often fatigue was reported in clinical trials. You could also be feeling fatigued due to the infection your body is fighting. Common symptoms of fatigue include loss of energy, feeling heavy and tired, and loss of interest in activities.

What you can do

If you are feeling fatigued, try taking a nap or limiting your activities until you are feeling better. If you continue to feel fatigued, talk with your doctor about other options.

Nausea

Nausea is a common side effect reported in clinical trials of Augmentin. Common symptoms include feeling queasy or as if you’re about to vomit.

What you can do

Sometimes, nausea can be relieved by a full stomach, so try eating food when you take your dose of Augmentin. You can also try drinking ginger ale, smelling peppermint, or using a nausea relief wristband to decrease your nausea. Talk with your doctor if your nausea does not go away.

Headache

Headaches were a reported side effect in clinical trials of Augmentin. Symptoms can include pain in your head or neck, dizziness, or fatigue.

What you can do

Talk with your doctor to see if you can take over-the-counter pain medications for your headache, such as Tylenol (acetaminophen) or Motrin (ibuprofen). Avoiding bright lights, screens, and loud noises and using warm or cold compresses may also help.

Intestinal infection

An intestinal infection due to the bacteria Clostridioides difficile has been reported in clinical trials of Augmentin. The most common symptom is severe diarrhea.

What you can do

If you experience any diarrhea, tell your doctor right away. If you have this infection, you will likely need antibiotic therapy. However, antibiotic treatment does not always work, and some people have needed surgery. Therefore, it’s important to tell your doctor right away about any diarrhea you experience.

Rash and itching

Rashes and itching are common side effects of Augmentin in clinical trials. Occasionally, a serious hypersensitivity reaction has been reported. These reactions are more likely if you are allergic to penicillin, cephalosporins, or multiple other allergens. Symptoms can include redness or discoloration, itchiness, swelling, or trouble breathing.

What you can do

Tell your doctor if you experience a rash or itching. If you think your symptoms are life threatening, call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Augmentin. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions. The conditions and factors to consider include:

Liver problems. Before you start treatment with Augmentin, tell your doctor if you have liver problems. In some cases, this drug may cause certain liver problems as a side effect. If you have had liver problems in the past, your risk of side effects may be higher. Your doctor will determine if Augmentin is the best treatment option for your condition.

Clostridium difficile-associated diarrhea. You may have diarrhea caused by Clostridioides difficile bacteria while taking Augmentin. Tell your doctor if you experience diarrhea that won’t go away while taking Augmentin or up to 2 months after you stop taking the drug. You may need medical treatment for this condition.

Superinfections. It’s possible for existing fungal or bacterial infections to get worse or spread when you take Augmentin. Talk with your doctor if you think the Augmentin is not helping your infection improve.

Skin rash. You may have an increased risk of developing a skin rash while taking Augmentin if you have mononucleosis (commonly called “mono”). Mono is an infection that is usually caused by the Epstein-Barr virus. If you have mono, ask your doctor if a different antibiotic may be a better option for you.

Development of drug-resistant bacteria. Taking Augmentin when you do not have a bacterial infection may cause bacteria to be resistant to the antibiotic. Do not take Augmentin unless your doctor prescribes it to you.

Phenylketonuria (buildup of the amino acid phenylalanine). Some forms of Augmentin contain an ingredient called phenylalanine. If you have phenylketonuria, ask your doctor if a different medication without phenylalanine may be a better option for you.

Drug interactions. Taking Augmentin with certain other medications may change how medications work or increase the chance of certain side effects. For example, taking Augmentin with combined oral contraceptives may lower the efficacy of the contraceptive. Talk with your doctor about all medications you take. Do not start or stop taking a medication without letting your doctor know.

Allergic reaction. If you’ve had an allergic reaction to Augmentin or any of its ingredients, your doctor will likely not prescribe Augmentin. Ask your doctor what other medications may be better options for you.

Alcohol with Augmentin

It’s unknown how alcohol interacts with Augmentin. However, drinking alcohol while taking Augmentin may increase your risk of certain side effects, such as nausea, vomiting, and liver problems.

If you drink alcohol, talk with your doctor about whether it’s safe to drink it while taking Augmentin.

Pregnancy and breastfeeding while taking Augmentin

It’s not known whether it’s safe to take Augmentin while you’re pregnant or breastfeeding.

Animal studies showed no harm to the fetus when pregnant rats were given Augmentin. However, it’s important to note that animal studies do not always indicate what may happen in humans.

Augmentin may pass into breast milk. Due to this risk, your doctor will likely not prescribe Augmentin when you are breastfeeding.

If you’re pregnant, breastfeeding, or planning either, talk with your doctor before starting Augmentin. They can advise you on the right treatment option for you.

Most side effects from taking Augmentin are mild and will resolve on their own or with treatment. Rarely, a side effect may be serious and need immediate medical attention.

If you’d like to learn more about Augmentin, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

  • More information about Augmentin. For details about other aspects of Augmentin, see this article.
  • Drug comparison. To learn how Augmentin compares with amoxicillin, read this article.
  • Interactions. For information about Augmentin’s interactions, see this article.
  • A look at infection. To learn about your condition, view our list of infectious disease articles.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.