Co-amoxiclav for infections

  • Co-amoxiclav is a type of penicillin and you should not take it if you are allergic to penicillin.
  • Space your doses out evenly over the day and complete the full course of this antibiotic, unless you are told to stop.
  • If you have an allergic reaction to co-amoxiclav (such as any swelling around your mouth, any difficulties breathing or a red rash) contact a doctor straightaway.
Type of medicine Penicillin antibiotic
Used for Infections (in adults and children)
Also called Augmentin®, Augmentin-Duo®
Available as Tablets, oral liquid and injection

Co-amoxiclav is used for bacterial infections, such as some respiratory infections, or infections of the urine, skin, bones or mouth. It is also used to prevent an infection from occurring if, for example, you are having an operation and you are at particular risk of getting an infection.

Co-amoxiclav contains two ingredients, amoxicillin and clavulanic acid. The first ingredient, amoxicillin, is a penicillin antibiotic which treats infection by killing bacteria. Some bacteria are able to produce a chemical which makes amoxicillin less effective. The second ingredient, clavulanic acid, stops this from happening. Clavulanic acid stops the chemical produced by the bacteria from working, and this allows the amoxicillin to kill the bacteria.

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking co-amoxiclav it is important that your doctor or pharmacist knows:

  • If you are pregnant or breast-feeding.
  • If you have glandular fever.
  • If you have kidney problems.
  • If you have liver problems, or if you have ever had jaundice after taking an antibiotic.
  • If you are taking other medicines, including those available to buy without a prescription, herbal and complementary medicines.
  • If you have ever had an allergic reaction to this or to any other medicine. This is particularly important if you have ever had a bad reaction to any penicillin antibiotic.
  • Before you start this antibiotic, read the manufacturer's printed information leaflet from inside the pack. The leaflet will give you more information about the specific brand of co-amoxiclav you have been given, and any possible side-effects from taking it.
  • Take co-amoxiclav exactly as your doctor has told you. Your doctor or pharmacist will tell you how much to take and when to take it. Your dose will also be on the label of the pack. Space the doses out evenly during the day.
  • You can take co-amoxiclav before or after food.
  • Even if you feel your infection has cleared up, keep taking this antibiotic until the course is finished, unless you are told to stop.This is to prevent the infection from coming back. A course of treatment with this antibiotic does not usually last for longer than 14 days.
  • If you forget to take a dose, take one as soon as you remember. Try to take the correct number of doses each day, but do not take two doses at the same time to make up.
  • If you still feel unwell after completing a course of co-amoxiclav, make an appointment to see your doctor again.
  • Some people develop thrush (redness and itchiness in the mouth or vagina) after taking a course of antibiotics. If this happens to you, speak to your doctor or pharmacist for advice.
  • If you (or your child) have been prescribed the oral liquid to take, you may find it causes some staining of the teeth. This is not permanent and will disappear soon after you (or your child) finish taking it.
  • If you are using combined oral hormonal contraception (the 'pill'), additional contraceptive precautions such as condoms are not required during a course of this antibiotic unless you are sick or have diarrhoea. If you need further advice, speak with your doctor or pharmacist..
  • This antibiotic may stop the oral typhoid vaccine from working. If you are having any vaccinations, make sure the person treating you knows that you are taking this medicine.
  • If you buy any medicines, check with a pharmacist that they are safe to take with your other medicines.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking co-amoxiclav.

Along with their useful effects, most medicines can cause unwanted side-effects, although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common co-amoxiclav side-effects What can I do if I experience this?
Feeling or being sick Try taking your dose before a mealtime
Diarrhoea Drink plenty of water to replace any lost fluids. If this continues, becomes severe, or contains blood, speak with your doctor straightaway
Thrush (redness and itchiness in your mouth or vagina) - this is due to a yeast infection If this happens to you, speak to your doctor or pharmacist for advice

Important: if you experience any of the following rare but serious symptoms, stop taking co-amoxiclav and contact your doctor for advice straightaway:

  • Any swelling of your face or mouth, any difficulties breathing, or a severe skin rash.
  • Jaundice (yellowing of your skin or the whites of your eyes).

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

  • Keep all medicines out of the reach and sight of children.
  • Keep co-amoxiclav oral suspension (liquid medicine) in a refrigerator, and do not store or use it for longer than seven days. This will have been made up by the pharmacy and it is important you do not use it after the expiry date on the bottle.
  • Store co-amoxiclav tablets in a cool, dry place, away from direct heat and light.
  • Never take more than the prescribed dose. If you suspect that someone has taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.
  • This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
  • Never keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
  • If you have any questions about this medicine ask your pharmacist.

Further reading & references

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.

Original Author:
Helen Allen
Current Version:
Peer Reviewer:
Dr John Cox
Document ID:
3609 (v25)
Last Checked:
20/02/2012
Next Review:
19/02/2015
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