Amoxicillin for infections

Authored by , Reviewed by Sid Dajani | Last edited | Meets Patient’s editorial guidelines

Make sure you tell your doctor if you are allergic to penicillin. Amoxicillin is a type of penicillin - do not take it if you are allergic to penicillin.

Space your doses out evenly over the day and complete the full course of the antibiotic, even if you feel your infection has cleared up. You can take amoxicillin either before or after food.

If you have an allergic reaction (such as any swelling around your mouth, any difficulties breathing or a red rash) contact a doctor for advice straightaway.

Type of medicineA penicillin antibiotic
Used forInfections (in adults and children)
Available asCapsules, oral liquid medicine, soluble tablets, sachets of powder and injections

What is amoxicillin used for?

Amoxicillin is used to to treat bacterial infections (not viral infections). Amoxicillin is mainly prescribed for different types of infection including; sinus and chest infections, urine infections, ear infections, and some dental infections. You may also be prescribed amoxicillin to prevent an infection from occurring if you are at particular risk of getting an infection. Amoxicillin is a penicillin antibiotic which treats infection by killing the germs (bacteria) responsible for the infection. Other types of antibiotics include cephalosporin antibiotics like Cefalexin®.

Amoxicillin is sometimes used to get rid of Helicobacter pylori. This is an infection often found in people with stomach ulcers. If you are prescribed amoxicillin for this reason, you will also be prescribed other medicines to take alongside it.

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

  • If you suspect you may have glandular fever (the symptoms are high temperature (fever), sore throat, swollen glands).
  • If you have an allergic condition, or if you have ever had an allergic reaction to a medicine. This is especially important if you have ever had a bad reaction to any penicillin antibiotic for example trouble breathing.
  • If you have any problems with the way your kidneys work for example kidney disease.
  • If you are pregnant or breastfeeding. Amoxicillin is not known to be harmful to babies; however, it is still important that you tell your doctor if you are expecting or breastfeeding a baby.
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
  • Before you start the amoxicillin treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about amoxicillin and will provide you with a full list of the side-effects you may experience from taking amoxicillin.. It will also detail the potential drug interactions of amoxicillin.
  • Take amoxicillin exactly as your doctor tells you to. It is usually taken three times daily, every eight hours. Your dose will be different to this if you are being treated with sachets of amoxicillin powder, or if you are taking amoxicillin to treat a stomach ulcer. Your doctor or pharmacist will tell you how you should take the medication, and this information will be printed on the label of the pack to remind you. It is important that you space out the amoxicillin doses evenly during the day.
  • If you have been given liquid medicine for a child, read the directions carefully to make sure you measure out the correct amount of medicine.
  • You can take amoxicillin either with or without food. The amoxicillin capsules should be swallowed whole with a drink of water.
  • If you have been supplied amoxicillin oral powder sachets, stir the powder from the sachet into 10-20 ml of water. Drink the solution as soon as possible after mixing it.
  • If you forget to take a dose of amoxicillin at the correct time, take one as soon as you remember. Try to take the correct number of doses each day, leaving at least four hours between doses. Do not take two doses of amoxicillin at the same time to make up for a missed dose.
  • If you (or your child) have been prescribed the oral liquid amoxicillin medicine, you may find that it causes some staining of the teeth. Brushing the teeth regularly helps to prevent this. Any staining usually disappears soon after the course of antibiotics is finished.
  • Even if you feel your infection has cleared up, keep taking the antibiotic until the course is finished (unless a doctor tells you to stop). This is to prevent the infection from coming back.
  • Antibiotics are prescribed in short courses of treatment. Your doctor will tell you how long your course of treatment will last - this is not usually for longer than 14 days. If you still feel unwell after finishing the course, go back to see your doctor.
  • Some people develop redness and itching in the mouth or vagina (thrush) after taking a course of antibiotics. If this happens to you, speak with your doctor or pharmacist for advice.
  • If you are taking birth control like the contraceptive 'pill' at the same time as this antibiotic, the effectiveness of the 'pill' can be reduced if you have a bout of being sick (vomiting) or diarrhoea which lasts for more than 24 hours. If this should happen, ask your doctor or pharmacist for advice about what additional contraceptive precautions to use over the following few days. There is no need to use additional precautions for any bouts of sickness or diarrhoea which last for less than 24 hours.
  • Amoxicillin can stop the oral typhoid vaccine from working so if you are due to have any vaccinations, make sure the person treating you knows that you are taking this antibiotic.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with amoxicillin. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common amoxicillin side-effects (these affect fewer than 1 in 10 people)What can I do if I experience this?
Feeling sick (nausea) or being sick (vomiting)Stick to simple foods. Try taking your doses of amoxicillin with something to eat if you are not already doing so
DiarrhoeaDrink plenty of water to replace any lost fluids. If the diarrhoea continues, becomes severe, or contains blood, let your doctor know straightaway
Redness and itching in the mouth or vagina (thrush)Speak with a pharmacist or your doctor for advice about treatment
Skin rashLet your doctor know as soon as possible as your treatment will need to be changed

Important: if you develop an itchy rash, swollen face or mouth, or have difficulty breathing, these may be signs that you are allergic to antibiotics called penicillins. Do not take any more amoxicillin and speak with your doctor or go to your local accident and emergency department straightaway.

If you experience any other symptoms which you think may be due to the antibiotic, call your doctor or pharmacist for further medical advice.

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.
  • If you have been given liquid medicine, this will have been made up by the pharmacy and lasts for 14 days. Make sure you check the expiry date on the bottle and do not use it after this date.

Never take more than the prescribed dose. If you suspect that you or someone else might have 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.

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 any dental treatment, tell the person carrying out the treatment which medicines you are taking.

Do not 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 and references

newnav-downnewnav-up