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Paracetamol (Acetaminophen)

A medicine used to treat mild to moderate pain.

Last Modified: 21 May 2024

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What is Paracetamol?

Paracetamol (Acetaminophen) (also known as Paracetamol) is a widely used over-the-counter (OTC) pain reliever and fever reducer. It is the active ingredient in various medications and is known for its analgesic and antipyretic properties. Unlike non-steroidal anti-inflammatory drugs (NSAIDs), it doesn't reduce inflammation.

This drug is synthesized through a process called acetylation, where a hydrogen atom in the phenol group of the compound p-aminophenol is replaced with an acetyl group.

Global Name

Generic Names:

  • Paracetamol: Widely used in European countries, including the United Kingdom and the Netherlands, as well as in many other parts of the world such as Australia, Brazil, South Africa, and India.  
  • Acetaminophen: The name commonly used in the United States, Canada, Japan, South Korea, Hong Kong, Iran, Colombia, and Venezuela. 

Global Brand Names:

Here are some of the global brand names for this common analgesic and antipyretic medication:

  • Panadol: The most famous paracetamol (acetaminophen) brand is available in more than 50 countries worldwide. 
  • Calpol: Another brand name, often used for pediatric formulations in the UK, India, South Africa, Turkey and the Philippines. 
  • Tylenol: A brand name primarily sold in the United States. 
  • Efferalgan: Commonly used in France and some other European countries. 
  • Tachipirina: available in Italy and Albania. 
  • Dafalgan: Used in Belgium and Switzerland. 
  • Tempra: A brand name used in some Latin American countries, Indonesia and the Philippines. 
  • Feverall: A brand of paracetamol (acetaminophen) in suppository form, available in the U.S. 

These names all refer to the same medication. It's important to note that while the active ingredient is the same, different countries may have different regulations and available medication formulations.


What is Paracetamol used for?

Paracetamol (Acetaminophen) is used to relieve:

  • Mild to moderate pain from headaches, muscle aches, menstrual periods, colds, and sore throats
  • Pain of osteoarthritis
  • Fever

How do you use Paracetamol?


  • Oral suspension
  • Tablets or caplets, capsules
  • Suppositories
  • Intravenous liquid for injection

Dosage information:

  • Infants and Children: Dose based on weight, please consult a paediatrician
  • Adults: 325-650 mg every 4 to 6 hours or 1,000 mg every 8 hours
  • Elderlies: Same as adults, but with increased caution


  • Children: Yes, with correct dosing
  • Adults: Yes
  • Elderlies: Yes, with caution

Who cannot take Paracetamol?

  • Individuals with severe liver disease
  • People with a known allergy to Paracetamol

Allergies and unsuitability:

  • Rare, but possible allergic reactions

Warnings and precautions:

  • Do not exceed the recommended dose; risk of liver damage
  • Can be taken with or without food

Interactions and contraindications:

  • Avoid alcohol to reduce the risk of liver damage
  • Check with a doctor if you take warfarin

Conditions where the drug should not be used:

  • Active liver disease
  • Known allergy to Paracetamol (Acetaminophen)

Side Effects

Common side effects are rare but may include nausea or rash. Severe side effects include allergic reactions and liver damage.

Paracetamol is safe when used as directed, but overuse can lead to serious health issues.

Pharmacist Tips

Storage information:

  • Keep in a cool, dry place away from children.
  • Do not freeze.

Handling instructions:

  • Use the measuring device that comes with the medication for the correct dose.


Where is Paracetamol available in Hong Kong?

Paracetamol is an over-the-counter (OTC) medication that can be sold without a prescription. It is found in all chain drug stores, including Mannings and Watsons.


Can you take Paracetamol (Acetaminophen) on an empty stomach?

Yes, Paracetamol (Acetaminophen) can be taken with or without food.

How long does Paracetamol (Acetaminophen) take to work?

Paracetamol (acetaminophen) typically starts to relieve pain or reduce fever within 30 to 60 minutes after oral intake. Its peak effects occur within 1 to 3 hours. Liquid formulations may be absorbed faster than pills. While individual metabolic rates and whether one has eaten can influence onset time, exceeding the recommended dose does not speed up relief and can cause harm. Always adhere to dosing guidelines to avoid the risk of liver damage.

How often can you take Paracetamol (Acetaminophen)?

Do not exceed the maximum daily amount; take only as needed, every 4-6 hours.

Can Paracetamol (Acetaminophen) be taken with other medications?

Check with a healthcare provider as Paracetamol (Acetaminophen) is a common ingredient in many OTC drugs, and you want to avoid overdose.

Is Paracetamol (Acetaminophen) safe for children and babies?

Yes, Paracetamol is safe for children at the recommended doses. There are infant and child formulations available. Always follow the instructions on the package or as directed by a healthcare professional.

What should I do if I forget a dose of Paracetamol (Acetaminophen)?

If you miss a dose, take it as soon as you remember unless it's near the time for your next dose. In that case, skip the missed dose and continue your regular schedule.

How long does the effect of Paracetamol (Acetaminophen) last?

Paracetamol's effects typically last about 4 to 6 hours. It is important to follow dosing instructions and not exceed the recommended amount, usually no more than 1,000 mg per dose and 4,000 mg per day for adults, to avoid the risk of toxicity.

This website provides content related to drug use and medicine for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Do not use the information on this website to diagnose or treat a health problem or disease without consulting a qualified healthcare provider. The website's owners and contributors are not liable for any repercussions, adverse effects, or consequences resulting from the use of any medication or information provided herein.

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