paracetamol at a glance
Medicine class
Analgesic and antipyretic: relieves pain and lowers fever.
Available forms
Tablets, oral suspensions, suppositories and intravenous infusion.
With food
Ordinary tablets and capsules can be taken with or without food.
Key safety point
Check pain, cold, flu and sleep remedies to avoid using more than one paracetamol-containing product.
What is paracetamol used for?
Selected UK products are licensed to relieve pain and reduce fever. Uses vary by formulation and age group.
Mild to moderate pain, including headache, migraine, toothache, sore throat, period pain, backache, muscular or rheumatic pain, and aches associated with colds or influenza.
Fever, including feverishness associated with colds, influenza or immunisation where specified by the product licence.
Suppositories may be useful when oral medicine is difficult to take, such as during nausea or vomiting.
Intravenous paracetamol is licensed for short-term moderate pain, particularly after surgery, and fever when intravenous treatment is clinically justified or other routes are unavailable.
How does paracetamol work?
Paracetamol reduces prostaglandin production involved in pain signalling and temperature regulation. Its precise actions are not fully defined but occur mainly within the central nervous system.
paracetamol preparations and strengths
Solution for infusion
Route: Intravenous
Strengths: 10 mg/mL, 1 g/100 mL
Caplet
Route: Oral
Strengths: 500 mg
Capsule
Route: Oral
Strengths: 500 mg
How to take paracetamol
Follow the instructions for the exact product because liquids and other formulations are not interchangeable. Do not use another paracetamol-containing medicine at the same time.
Swallow ordinary tablets with water. They may be taken with or without food.
Shake oral suspensions thoroughly and measure them using the supplied syringe, spoon or another suitable oral-measuring device.
Use suppositories rectally and administer them whole unless the exact product information specifically permits cutting.
Intravenous paracetamol must be prescribed and administered by a healthcare professional.
paracetamol side effects
Get urgent medical advice
- Severe allergic reaction, including facial or throat swelling, wheezing or difficulty breathing.
- Serious skin reaction with a spreading rash, blistering, peeling or sores affecting the mouth, eyes or genitals.
- Possible liver injury, including nausea, loss of appetite or yellow skin or eyes.
- Blood-cell disorders causing unusual bruising, bleeding, nosebleeds or repeated infections.
- High-anion-gap metabolic acidosis in susceptible, severely unwell or glutathione-depleted patients, particularly with prolonged exposure or concurrent flucloxacillin.
paracetamol in pregnancy
Paracetamol can be used throughout pregnancy for pain or fever and is the best-studied first-choice painkiller in this setting. Use should be limited to what is clinically needed; seek professional advice if symptoms persist, frequent use is required or other medicines are being considered.
paracetamol while breastfeeding
Paracetamol is a preferred painkiller during breastfeeding because only small amounts pass into breast milk. This applies to full-term, healthy infants; seek specialist advice after overdose, for an unwell or premature infant, or when using combination products.
paracetamol interactions
Check prescribed and non-prescribed medicines, particularly combination cold, flu and pain products.
Other paracetamol-containing medicines
Combining products can unintentionally cause overdose and serious liver injury.
Warfarin and other coumarin anticoagulants
Prolonged regular paracetamol use may increase anticoagulant effect and bleeding risk, so closer INR monitoring may be needed; occasional use has less effect.
Flucloxacillin
Concurrent use can contribute to pyroglutamic acidosis, particularly in severely ill, malnourished, renally impaired or otherwise glutathione-depleted patients.
Common questions about paracetamol
Answers are fully visible for fast scanning and source review.
Is Calpol the same medicine as paracetamol?
Calpol is a brand containing paracetamol. Check the exact product and strength because different liquids and brands are intended for different age groups.
Can paracetamol be taken with food?
Ordinary tablets and capsules can be taken with or without food. Follow product-specific instructions for specialised formulations.
Can adults take paracetamol with ibuprofen?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.