Amoxil (Amoxicillin) - Oral

What Is Amoxil?

Amoxil (amoxicillin) is a penicillin antibiotic used to treat a large variety of bacterial infections.

It works by binding to penicillin-binding proteins of bacteria. These bacteria are essential to the creation and maintenance of bacterial cell walls. If left alone, bacteria can rapidly multiply in the body and cause harm. Amoxil inhibits these penicillin-binding proteins so that susceptible bacteria are unable to continue replicating, killing the bacteria. This action is known as bactericidal killing.

Amoxil comes in various formulations. It is commercially available through prescription only as capsules, extended/immediate-release tablets, chewable tablets, and suspensions.

Drug Facts

Generic Name: Amoxicillin

Brand Name(s): Amoxil, Amoxicot, DisperMox, Moxatag, Moxilin, Trimox

Administration Route(s): Oral

Drug Availability: Prescription

Therapeutic Classification: Antibiotic

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Amoxicillin

Dosage Form(s): Tablet, powder, capsule

What Is Amoxil Used For?

Amoxil is a broad-spectrum oral antibiotic that can work against many different bacterial organisms. Antibiotic medications only treat bacterial infections, not viral infections (e.g., the common cold or the flu).

Healthcare providers prescribe amoxicillin to treat:

Amoxil is also used in combination with Biaxin (clarithromycin) and Prevacid (lansoprazole) to treat Helicobacter Pylori infection and duodenal ulcers, also known as peptic ulcers.


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How to Take Amoxil

Follow the drug label instructions to get the most optimal results from taking this medication.

Generally, you can take Amoxil with or without food. However, taking Amoxil without food can cause stomach upset. If an upset stomach occurs, you can reduce these symptoms by taking it after eating a meal. It is best to take extended-release formulations within one hour after eating a meal.

Swallow the capsules and non-chewable tablets whole; do not chew, break, or crush these.

For oral suspensions, shake the solution well before each use. Your pharmacist should include a measuring device with all suspensions. Use this measuring device (and not a household spoon or cup) for accurate dosing.

You can add measured doses of oral suspensions to milk, juice, water, ginger ale, or formula right before consumption to help with the taste. You must drink the entire mixture to get the full dose of the medication. For better taste, you can also request flavored sweeteners for the antibiotic suspension.

Space the doses evenly throughout the day. You can take them in the morning, afternoon, and bedtime. Continue to take the medication as directed by your healthcare provider, even if you begin to feel better. Stopping antibiotics before completing the entire therapy can cause bacteria to grow back. If the bacteria grow back stronger, you may need a higher dose or more potent antibiotic to cure your infection.


Store Amoxil at room temperature in a dry place. Do not keep this medication in the bathroom or kitchen.

You can store the liquid suspension in the refrigerator to make its taste more tolerable, but you should not keep it in the freezer. Do not discard any leftover liquid. Contact your local pharmacy for more information on how and where to discard medications.

Off-Label Uses

Healthcare providers may prescribe Amoxil for reasons other than what has been approved by the Food and Drug Administration (FDA). This is known as off-label use.

Amoxil is sometimes used off-label to treat:

  • Actinomycosis: Actinomycosis is a rare infection in which bacteria spreads throughout the body.
  • Anthrax (infection): Anthrax is a rare infectious disease. Amoxil's use will depend on anthrax vaccine status, vaccine series completion, immune status, and pregnancy/breastfeeding status.
  • Asplenia: Asplenia is when an individual does not have a spleen or the spleen is not working.
  • Bronchiectasis: Bronchiectasis is a permanent condition in which the lungs’ airways are widened, increasing the risk for mucus buildup and infection.
  • Endocarditis prophylaxis: Endocarditis is inflammation of the heart’s inner lining.

How Long Does Amoxil Take to Work?

Amoxil will begin to work right after you start taking it. You may start to feel better in a few days, but make sure you complete your entire treatment.

What Are the Side Effects of Amoxil?

This is not a complete list of side effects and others may occur. A medical professional can advise you on side effects. If you experience other effects, contact your pharmacist or a medical professional. You may report side effects to the FDA at or 1-800-FDA-1088.

Generally, Amoxil is well tolerated in people. However, it may cause some side effects in certain individuals. It’s important to be aware of Amoxil’s possible side effects and their severity.

Common Side Effects

The most common side effects of Amoxil include: 

  • Stomach pain
  • Nausea
  • Vomiting 
  • Headache 
  • Skin rash 
  • Diarrhea

Severe Side Effects

Serious side effects and their symptoms can include the following:

  • Clostridioides difficile-associated diarrhea: Broad-spectrum antibiotics like Amoxil can kill both good and bad bacteria in the body. When too much good bacteria is killed, there won’t be enough to control the C. difficile bacteria. A common symptom of severe infection due to C. difficile is persistent watery diarrhea. 
  • Stevens-Johnson syndrome: Stevens-Johnson syndrome is a rare but serious skin disorder resulting from medication use that your body does not like. Rashes and blistering that are extremely painful can occur from this, in addition to fever and body aches. 
  • Signs of an allergic reaction: Signs of an allergic reaction can include symptoms such as hives, itching, swelling, blistering, burning eyes, or trouble breathing. If you have experienced this with any penicillin antibiotics in the past, this must be communicated with your healthcare provider before use. 
  • Vaginal pain, itching, and discharge: Amoxil can kill off good bacteria that keep yeast growth in the vagina under control. Contact your provider if you have vaginal pain, itching, or discharge after using Amoxil. 
  • Bleeding/bruising: Antibiotics with broad spectrums of activity may affect the blood clotting system of your body. This is a rare but severe side effect that is of greater concern if you take blood-thinning medications.

Call your healthcare provider right away if you have any of these serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

Long-Term Side Effects

Your healthcare provider will prescribe Amoxil to take for a specific length of time. It is important to take this medication exactly as directed to avoid possible consequences.

The long-term and overuse of antibiotics like Amoxil can cause antibiotic resistance. When antibiotics are misused, bacteria can change their characteristics so that antibiotics are unable to work against them. When bacteria advances itself, infections can become much harder to treat for those who are infected.

Long-term antibiotic therapy can also kill too many good bacteria, making the body more vulnerable to other infections.

Report Side Effects

Amoxil may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Amoxil Should I Take?

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The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage forms (capsules, powder for suspension, and tablets):
    • For bacterial infections:
      • Adults, teenagers, and children weighing 40 kilograms (kg) or more—250 to 500 milligrams (mg) every 8 hours, or 500 to 875 mg every 12 hours.
      • Children and infants older than 3 months of age weighing less than 40 kg—Dose is based on body weight and must be determined by your doctor. The usual dose is 20 to 40 milligrams (mg) per kilogram (kg) of body weight per day, divided and given every 8 hours, or 25 to 45 mg per kg of body weight per day, divided and given every 12 hours.
      • Infants 3 months of age and younger—Dose is based on body weight and must be determined by your doctor. The usual dose is 30 mg per kg of body weight per day, divided and given every 12 hours.
    • For treatment of gonorrhea:
      • Adults, teenagers, and children weighing 40 kilograms (kg) or more—3-grams (g) taken as a single dose.
      • Children 2 years of age and older weighing less than 40 kg—Dose is based on body weight and must be determined by your doctor. The usual dose is 50 milligrams (mg) per kilogram (kg) of body weight per day, combined with 25 mg per kg of probenecid, taken as a single dose.
      • Children younger than 2 years of age—Use is not recommended.
    • For treatment of H. pylori infection:
      • Adults—
        • Dual therapy: 1000 milligrams (mg) of amoxicillin and 30 mg of lansoprazole, each given three times a day (every 8 hours) for 14 days.
        • Triple therapy: 1000 mg of amoxicillin, 500 mg of clarithromycin, and 30 mg of lansoprazole, all given two times a day (every 12 hours) for 14 days.
      • Children—Use and dose must be determined by your doctor.


Dosing changes may be necessary for certain patients.

Newborn Babies

Newborn babies (3 months of age or younger) do not yet have fully developed kidneys. This can delay the removal of medication from the body, increasing the risk for side effects. Newborns prescribed Amoxil will need modified dosing.

The recommended maximum dose of Amoxil for mild to moderate infection is 30mg/kg/day to be split into two doses (every 12 hours).


Dosing for children weighing 40 kg or more is based on adult recommendations. The prescriber may modify the child’s dose if they are older than 3 months and weigh less than 40 kg.

Older Adults

Adults aged 65 years and older should use this medication with caution to prevent the risk of kidney toxicity and side effects. Your provider may adjust your dose if you have severe kidney impairment.

Pregnancy and Breastfeeding

People who are pregnant can take Amoxil.

Although generally safe for nursing infants, it is important to consult with your medical provider before taking Amoxil.

Certain levels of the medication may pass through the milk directly to the infant when breastfeeding. However, because those levels are much lower than the amount in the blood, there is no significant risk for your child. Just as with pregnancy, Amoxil use is justifiable if needed.

Missed Dose

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 continue your regular intake schedule. Do not take extra doses or multiple doses at the same time. If you have missed several doses or an entire day’s worth of treatment, contact your healthcare provider for advice on what to do.

Overdose: What Happens If I Take Too Much Amoxil?

Generally, an overdose of Amoxil is not associated with significant symptoms beyond the side effects mentioned previously. Taking too much Amoxil can cause interstitial nephritis (inflammation of the kidney) and crystalluria (kidney irritation).

Symptoms of interstitial nephritis include: 

  • Blood in the urine
  • Fever
  • Fatigue
  • Swelling

Symptoms of crystalluria are cloudy urine, increased urge to urinate, and lower back pain.

What Happens If I Overdose on Amoxil?

If you think you or someone else may have overdosed on Amoxil, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Amoxil, call 911 immediately.


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If your or your child's symptoms do not improve within a few days, or if they become worse, check with your doctor.

This medicine may cause a serious allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a skin rash; itching; shortness of breath; trouble with breathing; trouble with swallowing; or any swelling of your hands, face, mouth, or throat after you or your child receive this medicine.

Amoxicillin may cause diarrhea, and in some cases it can be severe. It may occur 2 months or more after you stop taking this medicine. Do not take any medicine or give medicine to your child to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. If you have any questions about this or if mild diarrhea continues or gets worse, check with your doctor.

Before you have any medical tests, tell the doctor in charge that you or your child are taking this medicine. The results of some tests may be affected by this medicine.

In some young patients, tooth discoloration may occur while using this medicine. The teeth may appear to have brown, yellow, or gray stains. To help prevent this, brush and floss your teeth regularly or have a dentist clean your teeth.

Birth control pills may not work while you are using this medicine. To keep from getting pregnant, use another form of birth control along with your birth control pills. Other forms include a condom, a diaphragm, or a contraceptive foam or jelly.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Amoxil?

Amoxil is typically a well-tolerated medication. However, there may be reasons that you should not take this particular antibiotic.

Individuals with severe hypersensitivity to Amoxil or similar antibiotics should not take this medication. Notify your healthcare provider if you experience signs of an allergic reaction (e.g., hives, itching, swelling).

What Other Medications Interact With Amoxil?

Amoxil has minor drug interactions. It is important to let your healthcare provider know any other prescription and OTC medications you are taking.

Medications that may interact with Amoxil include:

  • Mycophenolate
  • Aminoglycosides 
  • Methotrexate
  • Acemetacin
  • Probenecid
  • Tetracycline antibiotics

Additionally, the combination of blood thinner medications and Amoxil can cause clotting difficulties. If you are taking blood thinners, your healthcare provider may monitor your blood clotting closely to determine if your medication doses need to be changed.

What Medications Are Similar?

There are several medications within the class of penicillin antibiotics.

Commonly prescribed antibiotics within this class include:

  • Penicillin: Typically used to treat strep throat infections
  • Oxacillin: Treats bacterial infections caused by susceptible gram-positive organisms
  • Amoxicillin/Clavulanate: Treats the symptoms of lower respiratory tract infections, bacterial sinusitis, and chronic obstructive pulmonary disease (COPD)
  • Ampicillin/Sulbactam: Used for abdominal, skin, and infections of the female reproductive system
  • Piperacillin/Tazobactam: Used to treat abdominal, skin, and female pelvic infections, as well as pneumonia

This is a list of drugs that are also prescribed for the targeted condition(s). It is NOT a list of drugs recommended to take with Amoxil. You should not take these drugs together. Ask your pharmacist or a healthcare practitioner if you have questions.

Frequently Asked Questions

  • Can I take Amoxil if I am allergic to penicillin?

    No, if you are truly allergic to penicillin, you should not take Amoxil. They are within the same class of medications, and your body is likely to react in the same negative way. If you have any concerns, you should contact your healthcare provider.

  • What can I do to prevent antibiotic resistance?

    Be sure to wash your hands, take antibiotics exactly as directed by your doctor, and do not save antibiotics for future use. In addition, being up to date with your immunizations can help to prevent bacterial infections as well.

    Lastly, do not share your antibiotics with others as their conditions may need a different therapy and a complete course.

  • Can I drink alcohol while taking Amoxil?

    To date, there is limited information on whether it is okay to drink alcohol while taking antibiotics, but it is generally not recommended. Drinking alcohol can affect your body’s healing process, cause dehydration, and enhance the potential side effects of Amoxil, such as nausea, vomiting, and diarrhea.

  • Why can’t I use antibiotics for my cold?

    Illnesses such as the common cold, flu, and certain cough/sore throat symptoms result from viral infections. Antibiotics should only be used for bacterial infections.

  • Will Amoxil make my birth control less effective?

    There are currently conflicting studies and information regarding the combination of antibiotics and birth control. Amoxil may not negatively impact the effectiveness of your birth control. However, you may want to use backup non-hormonal birth control (e.g., condom, diaphragm) throughout your antibiotic therapy and at least seven days after your treatment. Continue to take both medications as directed, and contact your healthcare provider if you have any concerns.

How Can I Stay Healthy While Taking Amoxil?

It is important to take complete control of your health, especially when your body is fighting off an infection with antibiotics. There are many things you can do to stay healthy and ensure others remain healthy too.

Treating health conditions does not stop at taking your antibiotic medication. Taking the initiative to make lifestyle changes can go a long way too.

Here are some examples of what you can do:

  • Maintain good personal hygiene: Handwashing with soap can prevent many infections and stop the spread of germs. 
  • Drink water: Diarrhea is a common side effect of antibiotics like Amoxil. Diarrhea can lead to dehydration due to increased loss of fluids. Drinking plenty of water is vital to ensure that you are hydrated and recover correctly. 
  • Eat a balanced diet: Fresh fruits and vegetables provide nutrients that can help to boost your immune system. 
  • Communicate: If your symptoms are not improving after therapy, it may mean you are still infected. Be sure to always communicate any concerns that you have to your healthcare provider.

Medical Disclaimer

Verywell Health's drug information is meant for education purposes only and not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare professional. Consult your doctor before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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