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Amoxicillin

1. About amoxicillin

Amoxicillin is an antibiotic.

It's used to treat bacterial infections, such as chest infections (including pneumonia), dental abscesses and urinary tract infections (UTIs).

It's used in children, often to treat ear infections and chest infections.

The medicine is only available on prescription. It comes as capsules or as a liquid that you drink. It's also given by injection, but this is usually only done in hospital.

2. Key facts

  • For most infections, you'll start to feel better in a few days.
  • The most common side effects of amoxicillin are feeling sick (nausea) and diarrhoea.
  • Liquid amoxicillin can stain your teeth. This doesn't last and is removed by brushing.
  • You can drink alcohol while taking amoxicillin.
  • Amoxicillin is also called by the brand name Amoxil.

3. Who can and can't take amoxicillin

Amoxicillin can be taken by adults, including pregnant and breastfeeding women.

Amoxicillin can be taken by children.

Amoxicillin isn't suitable for some people. To make sure amoxicillin is safe for you, tell your doctor if you:

  • have had an allergic reaction to amoxicillin or penicillin or any other medicines in the past
  • have liver or kidney problems
  • have recently had, or are about to have, any vaccinations

4. How and when to take it

The usual dose of amoxicillin is 250mg to 500mg taken 3 times a day. The dose may be lower for children.

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.

You can take amoxicillin before or after food.

Important

Carry on taking this medicine until you've completed the course, even if you feel better. If you stop your treatment early, the infection could come back.

How to take it

Swallow amoxicillin capsules whole with a drink of water. Do not chew or break them.

Amoxicillin is available as a liquid for children and people who find it difficult to swallow tablets.

If you or your child are taking amoxicillin as a liquid, it will usually be made up for you by your pharmacist. The medicine will come with a plastic syringe or spoon to help you measure out the right dose.

If you don't have one, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not give the right amount.

What if I forget to take it?

If you forget to take a dose, take it as soon as you remember, unless it's nearly time for your next dose. In this case, just leave out the missed dose and take your next dose as normal.

Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.

If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to remember your medicines.

What if I take too much?

Accidentally taking an extra dose of amoxicillin is unlikely to harm you or your child.

Speak to your pharmacist or doctor if you're worried or you take more than 1 extra dose.

5. Side effects

Like all medicines, amoxicillin can cause side effects, although not everyone gets them.

Common side effects

These common side effects happen in around 1 in 10 people. Keep taking the medicine, but talk to your doctor or pharmacist if these side effects bother you or don't go away:

  • feeling sick (nausea)
  • diarrhoea

Serious side effects

Serious side effects are rare and happen in less than 1 in 1,000 people.

Call a doctor straight away if you get:

  • diarrhoea (possibly with stomach cramps) that contains blood or mucus. If you have severe diarrhoea for more than 4 days you should also speak to a doctor
  • pale poo with dark pee, yellowing of the skin or the whites of your eyes (warning signs of liver or gallbladder problems)
  • bruising or skin discolouration
  • joint or muscle pain that comes on after 2 days of taking the medicine
  • a skin rash with circular red patches

Some of these serious side effects can happen up to 2 months after finishing the amoxicillin.

Serious allergic reaction

Around 1 in 15 people have an allergic reaction to amoxicillin.

In most cases, the allergic reaction is mild and can take the form of:

  • a raised, itchy skin rash
  • coughing
  • wheezing

Mild allergic reactions can usually be successfully treated by taking antihistamines.

In rare cases, amoxicillin can cause a serious allergic reaction (anaphylaxis).

Urgent advice: Contact a doctor straight away if:

  • you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
  • you're wheezing
  • you get tightness in the chest or throat
  • you have trouble breathing or talking
  • your mouth, face, lips, tongue or throat start swelling

These are warning signs of a serious allergic reaction. A serious allergic reaction is an emergency.

These are not all the side effects of amoxicillin. For a full list see the leaflet inside your medicines packet.

Information:

You can report any suspected side effect to the UK safety scheme.

6. How to cope with side effects

What to do about:

  • feeling sick (nausea) - stick to simple meals and do not eat rich or spicy food. It might help to take your amoxicillin after a meal or snack.
  • diarrhoea - drink plenty of fluids, such as water or squash to avoid dehydration. Signs of dehydration include peeing less than usual or having strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.

7. Pregnancy and breastfeeding

It's usually safe to take amoxicillin during pregnancy and while breastfeeding.

For more information about how amoxicillin can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPS) website.

Important

For safety, tell your doctor if you're trying to get pregnant, are already pregnant or if you're breastfeeding.

8. Cautions with other medicines

There are some medicines that don't mix well with amoxicillin.

Tell your doctor if you're taking these medicines before you start taking amoxicillin:

  • methotrexate
  • a blood thinner called warfarin
  • gout medicines called probenecid and allopurinol
  • other antibiotics

Mixing amoxicillin with herbal remedies and supplements

There are no known problems with taking herbal remedies and supplements alongside amoxicillin.

Important

For safety, tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.

9. Common questions

How does amoxicillin work?

Amoxicillin is a similar antibiotic to penicillin. It works by killing the bacteria that cause the infection.

When will I feel better?

For most infections, you should feel better within a few days.

It's very important that you keep taking amoxicillin until your course is finished. Do this even if you feel better. It will help stop the infection coming back.

What if I don't get better?

Tell your doctor if you don't start feeling better after taking amoxicillin for 3 days. Also tell them if, at any time, you start to feel worse.

Will it give me thrush?

Some people get a fungal infection called thrush after taking a course of antibiotics like amoxicillin. It happens because antibiotics kill the normal harmless bacteria that help to protect you against thrush.

Ask your pharmacist or doctor for advice if this happens to you.

Will it affect my contraception?

Amoxicillin doesn't stop contraceptive pills working, including the combined pill or emergency contraception.

However, if amoxicillin makes you vomit or have severe diarrhoea (6 to 8 watery poos in 24 hours) for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do.

Read more about what to do if you're on the pill and you're being sick or have diarrhoea.

Will it affect my fertility?

There's no firm evidence to suggest that taking amoxicillin will reduce fertility in either men or women.

However, speak to a pharmacist or your doctor before taking it if you're trying to get pregnant.

Does it stain teeth?

If you or your child take amoxicillin as a liquid medicine, it can stain your teeth. This doesn't last and should go after brushing your teeth well.

Amoxicillin capsules don't stain teeth.

Can I drive or ride a bike?

Yes, amoxicillin shouldn't affect you being able to drive or cycle.

Is there any food or drink I need to avoid?

You can eat and drink normally while taking amoxicillin.

Can I drink alcohol with it?

Yes, you can drink alcohol with amoxicillin.

Can lifestyle changes help urinary tract infections?

It's possible that a straightforward urinary tract infection (UTI) may clear up on its own without any treatment. However, it's usually best to treat a UTI with an antibiotic, or it could spread to the kidneys and lead to more serious problems.

Once treated, there are steps you can take to stop UTIs coming back:

  • do not use perfumed bubble bath, soap or talcum powder around your genitals - use plain, unperfumed products, and have a shower rather than a bath
  • go to the toilet as soon as you need to pee and always empty your bladder fully
  • stay well hydrated - aim to drink 6 to 8 glasses of fluid a day (water, lower-fat milk and sugar-free drinks, including tea and coffee, all count)
  • wipe your bottom from front to back when you go to the toilet
  • empty your bladder as soon as possible after having sex
  • do not use a contraceptive diaphragm or condoms with spermicidal lubricant on them - use another type of contraception instead
  • wear underwear made from cotton, rather than synthetic material like nylon, and avoid tight jeans and trousers

Although they won't do any harm, there's little evidence to show drinking cranberry juice or taking cranberry supplements helps treat or prevent UTIs.

Page last reviewed: 23 November 2018
Next review due: 23 November 2021