Allopurinol is a xanthine oxidase inhibitor medicine used to prevent build-up of uric crystals in the body. This build up can be caused by some illnesses or as a side effect of certain medicines.This page from Great Ormond Street Hospital (GOSH) explains what allopurinol is, how it is given and some of the possible side effects. Each person reacts differently to medicines, so your child will not necessarily suffer from every side effect mentioned. If you have any questions or concerns, please speak to your doctor, nurse or pharmacist.
How is allopurinol given?
What are the side effects?
Severe allergic reaction
Upset stomach, causing diarrhoea and/or constipation
Interactions with other medicines
- Keep all medicines in a safe place where children cannot reach them.
- Allopurinol tablets should be kept in a cool, dry place away from direct sunlight or heat.
- If your doctor decides to stop treatment with allopurinol or the medicine passes its expiry date, return any remaining medicine to the pharmacist. Do not flush it down the toilet or throw it away.
- If your child vomits straight after taking the dose, inform your doctor or nurse, as your child may need to take another one.
- If you forget to give your child a dose and it is within a few hours of when the dose was due, give it as soon as you remember. Otherwise, do not give this dose but wait until the next dose is due. Do not give a double dose.
Please read this information sheet from GOSH alongside the patient information leaflet (PIL) provided by the manufacturer. If you do not have a copy of the manufacturer’s patient information leaflet please talk to your pharmacist. A few products do not have a marketing authorisation (licence) as a medicine and therefore there is no PIL.
For children in particular, there may be conflicts of information between the manufacturer’s patient information leaflet (PIL) and guidance provided by GOSH and other healthcare providers. For example, some manufacturers may recommend, in the patient information leaflet, that a medicine is not given to children aged under 12 years. In most cases, this is because the manufacturer will recruit adults to clinical trials in the first instance and therefore the initial marketing authorisation (licence) only covers adults and older children.
For new medicines, the manufacturer then has to recruit children and newborns into trials (unless the medicine is not going to be used in children and newborns) and subsequently amend the PIL with the approved information. Older medicines may have been used effectively for many years in children without problems but the manufacturer has not been required to collect data and amend the licence. This does not mean that it is unsafe for children and young people to be prescribed such a medicine ‘off-licence/off-label’. However, if you are concerned about any conflicts of information, please discuss with your doctor, nurse or pharmacist.