Amoxicillin

Sounds like 'amox-i-cil-lin'

Amoxicillin is an antibiotic used to treat infections caused by bacteria. Find out how to take it safely and possible side effects.

Type of medicine Also called
  • Antibiotic (to treat infections)
  • Penicillin antibiotic
  • Amoxil®
  • Alphamox®

What is amoxicillin?

Amoxicillin is an antibiotic used to treat different infections caused by bacteria. Examples of infections amoxicillin may be used for include chest infections, dental infections and infections of the throat, ear and sinus. 

It works by killing or stopping the growth of bacteria (bugs) and getting rid of the infection. Amoxicillin belongs to a group of antibiotics called penicillins. Like all antibiotics, it is not effective against infections caused by viruses. 

Dose

In Aotearoa New Zealand amoxicillin is available as capsules (250 mg and 500mg), liquid and can be given as an injection in the hospital. 

  • The dose of amoxicillin will be depend on the type of infection. 
  • The usual dose of amoxicillin capsules in adults is 500 mg or 1000 mg 3 times a day.
  • Your doctor will advise you how long to take amoxicillin for (usually 3–7 days).
  • For most infections, you should feel better within a few days.
  • Always take your amoxicillin exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much to take, how often to take it and any special instructions.

How to take amoxicillin capsules

  • Timing of your doses:   You can take amoxicillin capsules with or without food. Swallow the capsules with a drink of water. Do not chew them. Try to space the doses evenly throughout the day. If you take it 3 times a day, this could be first thing in the morning, mid-afternoon and at bedtime. Ideally these times should be at least 4 hours apart.  
  • Missed dose: If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, take the next dose at the right time. Do not take extra doses to make up for a forgotten dose. If you are not sure what to do, ask your healthcare provider.
  • Finish the course: Take the whole course of antibiotics for the number of days your doctor has told you to. Do not stop taking it, even if you feel your infection has cleared up. If you stop your treatment early, your infection could come back.

For information on how to give amoxicillin to children, see amoxicillin information for parents and carers. 

Things to consider while you are taking amoxicillin

  • Amoxicillin does not have direct interactions with alcohol. This means that most people could have the occasional drink while taking it without any serious problems. However, if amoxicillin makes you feel sick (nauseous), do not drink alcohol as it will make you feel worse.
  • If you are taking the contraceptive pill, you do not usually need to use additional contraception if you're taking amoxicillin. But if the antibiotic or the illness it's treating causes diarrhoea (runny poo/hamuti) or vomiting (being sick), lasting more than 24 hours, absorption of the contraceptive pill may be affected. If this happens, ask your doctor or pharmacist for advice about contraception over the following few days. 

Possible side effects 

Like all medicines, amoxicillin can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Allergic reaction

Tell your healthcare provider if you have had an allergic reaction to a medicine, especially a penicillin antibiotic. True penicillin allergy is rare – fewer than 5 out of 10,000 people are allergic to penicillin.
Most people who think they have a penicillin allergy do not – read more about penicillins and penicillin allergy).

If you develop s
igns of an allergic reaction such as skin rash, itching, swelling of your lips, face and mouth, or difficulty breathing, stop taking amoxicillin and seek immediate medical attention. 

Other side effects

Side effects What should I do?
  • Nausea (feeling sick) or vomiting
  • Try taking amoxicillin with food.
  • If you are sick (vomit) less than 30 minutes after having a dose of amoxicillin, take the same dose again. But, if you are sick (vomit) and it is more than 30 minutes after having a dose of amoxicillin, you do not need to take another dose. Wait until the next normal dose.
  • Tell your doctor if these bother you.
  • Diarrhoea (loose, watery stools)     
  • This should settle after a few days.
  • Drink plenty of fluids such as water or squash to avoid dehydration.
  • Tell your doctor if it bothers you.
  • Vaginal itching, soreness or discharge (thrush)
  • Tell your doctor or pharmacist.
  • Teeth staining from liquid amoxicillin
  • This does not last and can be removed by brushing teeth.
  • Signs of an allergic reaction such as skin rash, itching, swelling of your lips, face and mouth, or difficulty breathing
  • Stop taking amoxicillin.
  • Tell your doctor immediately or phone Healthline 0800 611 116.
For more information on side effects, see the Medsafe consumer information leaflets below.

Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.

Learn more

The following links have more information on amoxicillin.

NZ Formulary

Alphamox capsules and liquid Medsafe Consumer Information, NZ

References

Additional resources for healthcare professionals

When is an allergy to an antibiotic really an allergy? BPAC, NZ, 2015

Credits: Health Navigator Pharmacists. Reviewed By: Maya Patel, MPharm PGDipClinPharm, Auckland Last reviewed: 18 Feb 2022