What is paracetamol and how does it work?
Paracetamol is a common pain killer (analgesic). It can also lower raised body temperature (fever). It is used for relief of fever, headaches, the pain of arthritis and other minor aches and pains, including pain from colds, flu and period pain.
It is thought that paracetamol works in the brain to prevent the release of substances that increase pain and temperature.
Paracetamol provides relief of pain and high temperatures within 30 minutes of taking a dose.
Examples of brand names: Dymadon, Febridol, Panadol, Panamax, Paralgin, Panadol Osteo.
How is it used in arthritis?
Paracetamol is usually the first medicine doctors recommend for the relief of all types of musculoskeletal pain including arthritis. Unlike ibuprofen (brand name Nurofen) and other non steroidal anti-inflammatories (NSAIDs), paracetamol is not effective in reducing the inflammation associated with arthritis.
You can find out more about NSAIDs from the separate ARA information sheet on NSAIDs.
When taken regularly paracetamol may help to manage severe pain and can reduce the need for stronger pain medicines or NSAIDs. This may help reduce the side effects from these other medicines.
How is paracetamol taken?
Paracetamol is usually taken by mouth in tablet or capsule form. It is also available as liquids and rectal suppositories.
What is the dosage?
Paracetamol usually comes in a 500mg tablet or capsule. It is also available in slow release (SR) 665mg tablets. The usual dose for adults and children 12 years and older is 2 tablets.
Liquid paracetamol is available for younger children. For over the counter paracetamol the dose depends on the child’s age.
If your child is prescribed paracetamol regularly the usual dose is 15mg per kg of body weight.
Liquid paracetamol comes in different strengths so it is very important you check the strength to ensure you don’t take or give more than is recommended.
The doses in the table below are a guide only – check with your doctor or pharmacist to determine exactly what dose you should be taking. The dose may need to be reduced if you have liver problems.
How often should it be taken?
Paracetamol can be taken when needed, that is when you feel the pain, or it may be taken regularly to manage persistent pain. Regular dosing is recommended to treat the persistent pain that may be associated with arthritis.
It is usually taken every 4 to 8 hours depending on the type of preparation. For example, for arthritis the dose could be two slow release (SR) tablets every 8 hours such as 8am, 2 pm and bedtime.
The side effects of paracetamol are not increased if you take it regularly provided you do not exceed the recommended maximum daily dose.
Always follow the instructions provided in the packaging unless otherwise directed by your doctor.
If the pain or temperature is not controlled do not take more than the recommended dose. Contact your doctor so that the situation can be reassessed. Ask your doctor or pharmacist if you are uncertain about how often to take your medicine.
When taken regularly paracetamol may be the only painkiller needed or it may reduce the need for stronger medicines, including NSAIDs.
How long is the treatment continued?
Treatment with paracetamol can be for a short period or long term. The side effects are not increased with long term treatment provided you do not exceed the recommended maximum daily dose.
Are there any side effects?
Most people who take paracetamol at recommended doses do not have side effects. Paracetamol does not affect blood clotting, worsen asthma or affect the function of the kidneys. It also does not increase blood pressure or increase the risk of heart attacks.
Rare side effects
- Stomach pains and nausea have been rarely reported.
- Allergy to paracetamol can occur very rarely with a variety of skin rashes.
Effects associated with overdose
Paracetamol is very safe in recommended doses but because of its wide availability in many different products, accidental overdoses can occur if precautions are not taken. Severe damage to the liver and kidneys can occur when more than the recommended dose is taken. On some occasions, overdosing of paracetamol has caused death. See Important things to remember below.
What other precautions are necessary?
Dose in liver disease
- Paracetamol is broken down in the liver. It is therefore important that you tell your nurse / doctor / pharmacist if you have any liver problems as the dose may need to be reduced.
- Usually blood tests are not required for people taking paracetamol.
Use with other medicines
- Anticoagulants e.g. warfarin can be taken safely with paracetamol. If you are taking the maximum dose of paracetamol (4 grams a day) on a regular basis, more frequent monitoring of warfarin is required.
- Aspirin can be taken safely with paracetamol in the low doses used for preventing heart attack and stroke.
- It is safe to take paracetamol with antibiotics for an infection.
- It is generally safe to take paracetamol with NSAIDs. Check with your doctor if you are taking NSAIDs regularly.
Use with alcohol
- Paracetamol can be used safely with a moderate intake of alcohol. However drinking more than 4 standard drinks on one occasion, even if infrequently, is strongly discouraged.
Use in pregnancy and breastfeeding
- Paracetamol can be taken safely during pregnancy or when breastfeeding.
How to store paracetamol
Store paracetamol in a cool, dry place, away from direct heat and light.
Keep all medicines out of reach of children.
Important things to remember
There is a limit to the amount of paracetamol that can be safely taken in a 24 hour period. You MUST see your doctor as soon as possible or go to the nearest emergency department if you think you have taken too much paracetamol.
- For otherwise healthy adults the maximum daily dose is 4 grams per day (6-8 tablets, depending on the strength of the tablets). This may be less if you have severe liver problems, or are frail or elderly
- Doses for children depend on their weight and must be carefully calculated.
- Be aware that other medicines may contain paracetamol, including cold and flu preparations and other pain preparations. Check the ingredients of such medicines before you take them. If you do take other medicines containing paracetamol be sure to consider these and not exceed the recommended total daily dose of paracetamol. There are many brands of paracetamol. These and any other medicines containing paracetamol will have the generic name paracetamol on the packet or bottle.
- It is also important to tell your nurse / doctor / pharmacist about any other medicines you are taking.
This information has been produced by the Australian Rheumatology Association (ARA) to help you understand the medicine that has been prescribed for you. Please read it carefully and discuss it with your doctor. The information in this sheet has been obtained from various sources and has been reviewed by the ARA. It is intended as an educational aid and does not cover all possible uses, actions, precautions, side effects, or interactions of the medicines mentioned. This information is not intended as medical advice for individual problems nor for making an individual assessment of the risks and benefits of taking a particular medicine. It can be reproduced in its entirety but cannot be altered without permission from the ARA. The NHMRC publication: How to present the evidence for consumers: preparation of consumer publications (2000) was used as a guide in developing this publication.