Paracetamol 500mg Product Information
What is paracetamol?
Paracetamol is one of the most widely used painkillers that can help relieve mild to moderate pain and reduce a high temperature.
It can be used for headache, tension headache, migraine, toothache, period pain, backache, rheumatic and muscular pain, pain caused by mild arthritis, as well as sore throat, the aches and pains associated with colds and flu.
Paracetamol is not a non-steroidal anti-inflammatory drug (NSAID) and has weak anti-inflammatory effects. While paracetamol is generally less likely to cause stomach irritation than NSAIDs such as ibuprofen, an anti-inflammatory medicine can be more appropriate for some types of pain where inflammation is the primary cause.
How to take paracetamol 500mg tablets
Always take paracetamol exactly as described in the Patient Information Leaflet included with your medicine, or as advised by your GP or pharmacist.
For adults aged 18 and over:
- Take one or two 500mg tablets every 4 to 6 hours as needed
- Swallow the tablets with water
- Leave at least four hours between doses
- Do not take more than four doses in any 24-hour period
- Do not take more than eight 500mg tablets in 24 hours, equivalent to 4,000mg or 4g of paracetamol
- Do not take more than the recommended dose
The maximum daily dose includes paracetamol from every source. If you also use a cold and flu remedy, combination painkiller or another medicine, check whether it contains paracetamol before taking it.
How does paracetamol work?
Paracetamol works mainly within the central nervous system, including the brain and spinal cord. The exact way paracetamol produces its pain-relieving effect is not fully understood. It is thought to reduce the activity of chemicals involved in transmitting pain signals and regulating body temperature. This helps relieve pain and reduce a high temperature.
How long does paracetamol take to work?
Paracetamol can start to relieve pain from around 30 minutes after taking a dose, with the maximum pain-relieving effect generally reached within 1 to 2 hours.
The pain-relieving effect typically lasts around 4 to 5 hours.
If your pain has not improved after taking a dose, do not take another dose sooner than four hours after the previous dose. Speak to a pharmacist or GP if paracetamol is not providing enough pain relief.
Who can take paracetamol 500mg tablets?
Most adults can take paracetamol.
The recommended adult dose is one or two 500mg tablets every 4 to 6 hours, as needed.
Some adults may need additional advice before taking paracetamol because of their health, other medicines or individual risk factors. If you are unsure whether paracetamol is suitable for you, speak to a pharmacist or your GP before taking it.
Who should not take paracetamol?
Do not take Paracetamol 500mg Tablets if:
- You are allergic to paracetamol or any of the other ingredients in the tablets
- You are already taking another medicine that contains paracetamol
Paracetamol can be found in many other cold and flu remedies and combination painkillers. Always check the ingredients of any other medicines you are taking, as using more than one paracetamol-containing product can cause you to exceed the recommended dose without realising.
Who should speak to a pharmacist or GP before taking paracetamol?
Speak to a pharmacist or GP before taking paracetamol if you:
- Have liver or kidney disease, including liver disease caused by alcohol
- Regularly drink heavily
- Are malnourished or have an eating disorder
- Are severely unwell, including if you have sepsis or severe kidney impairment
- Have mild arthritis and need to take painkillers every day
- Are unsure whether another medicine you take contains paracetamol
A rare but serious condition called high anion gap metabolic acidosis has been reported in people with certain risk factors, including severe kidney impairment, sepsis, malnutrition or chronic alcohol use, and in people taking paracetamol with flucloxacillin.
This has been reported when paracetamol is used at regular doses for a prolonged period or when paracetamol is taken together with flucloxacillin. Symptoms can include deep or unusually rapid breathing, drowsiness, nausea and vomiting. Seek urgent medical advice if these symptoms occur.
Which medicines interact with paracetamol?
Some medicines can interact with paracetamol:
- Flucloxacillin (an antibiotic). Taking flucloxacillin with paracetamol has been associated with a rare but serious condition called high anion gap metabolic acidosis, particularly in people who have other risk factors such as severe kidney impairment, sepsis, malnutrition or chronic alcohol use. Speak to a GP or pharmacist before taking these two medicines together.
- Warfarin or other coumarin anticoagulants. Occasional doses of paracetamol are not expected to have a significant effect. However, taking paracetamol regularly on a daily basis can increase the anticoagulant effect and the risk of bleeding. Speak to your GP or anticoagulant clinic if you need to take paracetamol regularly.
- Metoclopramide or domperidone (used for nausea and vomiting). Tell your GP or pharmacist if you take either of these medicines.
- Colestyramine (used to lower cholesterol). Colestyramine can reduce the absorption of paracetamol. Avoid taking colestyramine within one hour of taking paracetamol.
Other medicines can also interact with paracetamol. Tell your GP or pharmacist about all prescription medicines, over-the-counter medicines, supplements and herbal products you use.
How long can I take paracetamol for?
Do not take paracetamol for more than three days at a time unless your GP tells you to.
Speak to a GP if your pain or fever has not improved after three days, if you feel worse or if your symptoms keep returning. Seek medical advice sooner if you develop a high fever or signs of another infection.
If a healthcare professional has advised you to take paracetamol for longer as part of the treatment of an ongoing condition, follow the instructions they have given you.
What should I do if I forget a dose?
If you forget a dose, do not take a double dose to make up for it. Take the next dose at the usual time if you still need pain relief, making sure that there are at least four hours between doses.
What should I do if I take too much paracetamol?
Seek urgent medical advice immediately if you take more paracetamol than recommended, even if you feel completely well.
Taking too much paracetamol can cause delayed, serious liver damage. You may initially have few or no symptoms, so do not wait to see whether you feel unwell before seeking help.
Contact NHS 111 straight away for advice. If you are advised to go to A&E, take the medicine packaging, any remaining tablets and details of any other medicines you have taken with you.
Treatment for paracetamol overdose is most effective when it is started early. Call 999 if there is an immediate medical emergency.
What are the side effects of paracetamol?
Like all medicines, paracetamol can cause side effects, although not everybody experiences them. Side effects are uncommon, but some can be serious.
Stop taking paracetamol and seek medical advice immediately if you experience:
- An allergic reaction, which may include a rash, itching, swelling of the mouth or face or shortness of breath
- A severe skin reaction, including skin peeling, blistering or mouth ulcers
- Breathing problems
- Unexplained bruising or bleeding
- Nausea, sudden weight loss or loss of appetite
- Yellowing of the skin or whites of the eyes
High anion gap metabolic acidosis, a serious increase in the acidity of the blood, has also been reported in people with certain risk factors, including severe illness, severe kidney impairment, sepsis, malnutrition or chronic alcohol use, and in people taking paracetamol with flucloxacillin.
Symptoms can include deep or unusually rapid breathing, drowsiness, nausea and vomiting. Seek urgent medical advice if these symptoms occur.
A full list of possible side effects is provided in the Patient Information Leaflet supplied with your medicine.
Can I drink alcohol while taking paracetamol?
Avoid drinking alcohol while taking paracetamol to reduce the risk of side effects and liver damage.
Regular or heavy alcohol consumption can increase the risk of liver damage associated with paracetamol. If you regularly drink heavily or have liver disease caused by alcohol, speak to a pharmacist or GP before taking paracetamol.
Can I take paracetamol when pregnant?
Paracetamol can be used during pregnancy when pain relief or treatment for a fever is needed.
If you are pregnant, think you may be pregnant or are planning to have a baby, speak to your GP, pharmacist or midwife before taking paracetamol.
Use the lowest effective dose for the shortest possible time and as infrequently as possible. If your pain or fever does not improve or you find that you need paracetamol regularly, seek medical advice.
Can I take paracetamol when breastfeeding?
Paracetamol can be taken while breastfeeding. It passes into breast milk in small amounts but is unlikely to affect a breastfed baby when taken at recommended doses.
Speak to your GP, pharmacist or midwife if you need to take paracetamol regularly or have any concerns about your baby.
How should I store paracetamol?
Keep paracetamol tablets out of the sight and reach of children.
Do not use the tablets after the expiry date shown on the pack. The expiry date refers to the last day of the month stated.
Do not dispose of unused or expired medicines in household waste or wastewater. Return medicines you no longer need to a pharmacy for safe disposal.