Amoxicillin or Co-amoxiclav/Amoxicillin-Clavulanate (High Dose Therapy)

Medication Information Leaflet

What is this medication for?

The following leaflet addresses the use of higher doses of amoxicillin and co-amoxiclav/amoxicillin-clavulanate in children when treating their infections.

Both Amoxicillin and Co-amoxiclav/ Amoxicillin-Clavulanate contain amoxicillin as the active ingredient. Amoxicillin belongs to a group of antibiotics known as penicillin, and is used to treat a wide range of infections caused by bacteria, including infections of the chest (pneumonia), middle ear (otitis media), sinuses (sinusitis), tonsils (tonsillitis), urinary tract, and skin and soft tissue.

High-dose amoxicillin (such as 80 to 90mg/kg/day) is usually prescribed to overcome the antibiotic resistance that has developed to the common bacteria that may cause these infections such as the following:

  • Chest (pneumonia),
  • Ear (otitis media), and/or
  • Sinuses (sinusitis)

How should I take/use this medication?

  • Amoxicillin or Co-amoxiclav/Amoxicillin-Clavulanate is usually taken two or three times a day.
  • You may take this medication after food to reduce stomach discomfort.

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if:

  • You are allergic to this medication or any of the other ingredients of this medication.
  • You are taking any other medications, including supplements, traditional medications and herbal remedies.

What are some common side-effects of this medication?

Some common side effects that you may experience include

  • Nausea and upset stomach
    • Take the medication with or after food
  • Diarrhoea
    • Drink plenty of water to stay hydrated

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following:

  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

Very rarely, this medication may cause severe watery and/or bloody diarrhea, fever and painful stomach cramps. This can happen one to two days after you start taking an antibiotic, up to several weeks after you finish taking the antibiotic. This is due to overgrowth of the bacterium, C. difficile, in the colon.

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

What food or medication should I avoid when I take this medication?

Take probiotics at least 2 hours apart from antibiotics as the antibiotics may reduce the effectiveness of probiotics.

How should I store this medication?

Depending on whether you are taking the tablet or the suspension; the storage conditions may differ. Ask your healthcare professionals about the proper storage conditions of the antibiotic you are taking.

How should I throw away this medication safely?

Pack the medication into a bag and bring it back to the pharmacy where you received the medication from.


If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on January 2024


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