Can you help us improve NHS Choices?

Take part in our survey to share your views

Amoxicillin Trihydrate (Amoxicillin 500mg capsules)

Side effects

Information specific to: Amoxicillin 500mg capsules when used in Bacterial infections.


A medicine is only made available to the public if the clinical trials have shown that the benefits of taking the medicine outweigh the risks.

Once a medicine has been licensed, information on the medicine's effects, both intended and unintended, is continuously recorded and updated.

Some side-effects may be serious while others may only be a mild inconvenience.

Everyone's reaction to a medicine is different. It is difficult to predict which side-effects you will have from taking a particular medicine, or whether you will have any side-effects at all. The important thing is to tell your prescriber or pharmacist if you are having problems with your medicine.

Common: More than 1 in 100 people who take Amoxicillin trihydrate

  • diarrhoea
  • nausea
  • skin rash or rashes - erythematous rashes have been reported in people with glandular fever

Uncommon: More than 1 in 1000 people who take Amoxicillin trihydrate

  • itching
  • urticaria
  • vomiting

Very rare: Fewer than 1 in 10,000 people who take Amoxicillin trihydrate

  • abnormal laboratory test results
  • allergic or hypersensitivity reactions such as angioedema, vasculitis or anaphylactic reactions - some of these reactions may be fatal. You should seek medical advice if you get hypersensitivity reactions
  • black hairy tongue
  • blood and bone marrow problems
  • changes in blood clotting time
  • changes to teeth colour - this may happen in children and can usually be removed by brushing the teeth
  • colitis
  • convulsions
  • feeling dizzy
  • hyperactivity
  • jaundice
  • kidney problems
  • liver problems
  • pseudomembranous colitis
  • skin and mucous membrane infection
  • skin problems including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis or certain types of dermatitis

The frequency of these side-effects is unknown

  • may affect the results for certain tests
  • overgrowth of micro-organisms that are not affected by Amoxicillin trihydrate

If you feel unwell or if you have concerns about a side-effect, you will need to seek advice. If you feel very ill, get medical help straight away. Contact your prescriber, pharmacist, nurse or call 111.

Content provided by Datapharm

Yellow Card scheme

The Yellow card Scheme is vital in helping the MHRA monitor the safety of the medicines and vaccines that are on the market.

Before a medicine is granted a licence so that it can be made available in the United Kingdom, it must pass strict tests and checks to ensure that it is acceptably safe and effective. All effective medicines however, can cause side effects.