Paracetamol

What is Paracetamol used for?

Paracetamol (also known as acetaminophen) is a widely used pain reliever and fever reducer. It acts mainly on the central nervous system to inhibit prostaglandin synthesis, reducing pain and lowering body temperature, though it has weak anti-inflammatory effect. It is used for fever, headache, toothache, menstrual pain and mild-to-moderate muscle pain, and is one of the most commonly used over-the-counter painkillers in Hong Kong.

How to take Paracetamol and adjust the dose

Adults and adolescents 12+: typically 500-1000mg (1-2 standard tablets) every 4-6 hours, not exceeding 4000mg (8x 500mg tablets) in 24 hours. Panadol Extend (extended-release): 2 tablets every 6-8 hours, max 6 tablets/day. May be taken with or without food. Children's doses must be calculated by weight — refer to the product packaging or ask a pharmacist rather than estimating from the adult dose. If a dose is missed, take it at the next scheduled time; do not double up. Paracetamol overdose can cause serious, potentially delayed-onset liver damage — seek medical help immediately if overdose is suspected, even without early symptoms.

Paracetamol side effects

• Common: generally well tolerated, side effects are uncommon
• Rare/serious: allergic reaction (rash, throat/tongue swelling, breathing difficulty), liver damage (nausea, jaundice), blood cell problems (easy bruising, nosebleeds)

Who should not take Paracetamol?

• Known allergy to paracetamol
• Severe liver impairment requires medical assessment
• Avoid combining with other products containing paracetamol (risk of cumulative overdose)
• Higher risk in chronic heavy alcohol use
• Caution with concurrent colestyramine, imatinib and similar drugs