Paracetamol is a painkiller for mild to moderate pain. It can also control high temperatures (fever). It has a number of different brand names, for example Panadol, Anadin and Calpol.

Paracetamol can also be in other medicines such as Anadin Extra and cold remedies like Beechams and Benylin. In America it is also known as acetaminophen or Tylenol. 

How paracetamol works

Paracetamol seems to work by blocking chemical messages in the brain that tell us we have pain. 

How you have paracetamol

You can take paracetamol as:

  • tablets
  • capsules
  • caplets
  • soluble tablets
  • a syrup that you drink
  • an injection into a vein (this is only used in hospitals)

You can get paracetamol on prescription or buy it from a pharmacy or other shops such as your local supermarket. There is a limit on the amount you can buy for example a supermarket can only sell packets of 16 tablets. And a pharmacy will only allow you to buy 32 tablets at one time. 

Taking your tablets or capsules

You must take tablets and capsules according to the instructions your doctor or pharmacist gives you.

You should take the right dose, no more or less.

Into your bloodstream

You can have the drug through a thin short tube (a cannula) that goes into a vein in your arm each time you have treatment.

Or you might have it through a long line: a central line, a PICC line or a portacath.

These are long plastic tubes that give the drug into a large vein in your chest. The tube stays in place throughout the course of treatment.

When you have it

The dose you take depends on the amount you need to control your pain. You can take paracetamol to help control cancer pain or for other reasons such as headaches or a high temperature. You might take it at the same time as other painkillers or in between taking them. 

Your doctor, pharmacist or nurse will give you instructions about when to take paracetamol and how much to have. 

The normal dose for an adult is 1 to 2 tablets normal strength (500mg to 1,000mg) every 4 to 6 hours. You should not take more than 8 normal strength tablets (4,000mg) in 24 hours.

When you are having paracetamol and chemotherapy

During chemotherapy treatment you need to know if you have a high temperature. Having paracetamol for pain control can hide a high temperature caused by chemotherapy treatment. Take your temperature beforehand, if you have a high temperature contact your advice line before taking paracetamol. 

Side effects

How often and how severe the side effects are can vary from person to person. They also depend on what other treatment you are having. For example, your side effects could be worse if you are also having other drugs or radiotherapy.

When to contact your team

Your doctor, nurse, or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

  • you have severe side effects 
  • your side effects aren’t getting any better
  • your side effects are getting worse
Early treatment can help manage side effects better.

We haven't listed all the side effects here. Remember it is very unlikely that you will have all of these side effects, but you might have some of them at the same time.

Occasional side effects

Each of these effects can happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have:

  • itchy skin
  • rash

Rare side effects

Each of these effects happens in fewer than 1 in 100 people (fewer than 1%). You might have one or both of them. They include:

  • blood disorders
  • a drop in blood cells called platelets - these help you blood clot

Rare side effects of paracetamol injected into the blood stream (a vein)

Each of these effects might happen between 1 in 1,000 people (0.1%) to 1 in 10,000 people (0.01%). You might have one or more of them. They include:

  • feeling tired and weak
  • low blood pressure - you might feel lighted headed and dizzy
  • liver changes - usually mild and unlikely to cause symptoms
  • allergic reaction - can cause breathlessness, wheezing or swelling of the lips, face or throat. Tell the nurse or doctor straight away if you have any of these.
  • a drop in white blood cells

Other medicines, foods and drink

Paracetamol can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.

Remember that many over the counter medicines contain paracetamol, for example cold and flu remedies. Always check the packets of any other medicines you are taking to find out if they contain paracetamol. If you are taking paracetamol, do not take any other medicine containing paracetamol.

More information about this treatment

For further information about this treatment go to the electronic Medicines Compendium (eMC) website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

This page is due for review. We will update this as soon as possible.

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