The recommended dosage of paracetamol in adults is two 500mg tablets (i.e. 1gm paracetamol) every four to six hours, not exceeding eight tablets (4gms) in any 24 hour period (1). This dosage may be continued for several days. If pain relief is required for a longer period it should be with the supervision of a doctor.
Children's dosages vary with the age of the child and the type of product, therefore the instructions on the pack should always be followed.
In general, children's dosages are based on a single dose of 10mg paracetamol per kilogram bodyweight, which can be repeated 4-6 hourly, not exceeding four doses per 24 hours.
On a doctor's recommendation only, paracetamol may be given to a 2 month old child following immunisation as a single dose of 60mg (i.e. 2.5mL paracetamol liquid (oral suspension) at a strength 120mg per 5 mL).
For children under 3 months, on a doctor's advice only, the dosage is 10mg paracetamol per kilogram body weight (5mg/kg if jaundiced).
For a child 3 months to 1 year of age a dose of between 60mg and 120mg (i.e. 2.5mL to 5mL of paracetamol liquid (oral suspension) at a strength of 120mg/5mL) may be repeated every 4-6 hours to a maximum of 4 doses in 24 hours.
For a child 1 to 5 years of age 120mg to 250mg (i.e. 5mL to 10mL of paracetamol liquid (oral suspension) at a strength of 120mg/5mL) may be repeated every 4-6 hours to a maximum of 4 doses in 24 hours.
For a child 6 to 12 years of age 250mg to 500 mg (i.e. 5mL to 10mL paracetamol liquid (oral suspension) at a strength of 250mg/5mL) may be repeated every 4-6 hours to a maximum of 4 doses in 24 hours.
These dosages have been found to be effective, well tolerated and safe (2) in OTC usage and there are no circumstances in which they should be exceeded. If this dosage is not proving effective, then a pharmacist or doctor should be consulted for further advice.
In general the recommended dosages shown above should be followed. If, in a hospital setting, a higher dosage is considered desirable it is the responsibility of the prescribing physician. As there is no clear threshold at which toxicity may occur in an individual patient, it has been recommended that where a higher dosage is prescribed for an extended period, liver function should be monitored (2).
1 British National Formulary, Vol. 40; September 2000
2 OICPC Therapeutic Highlights; Progress in Palliative Care (2000); 8 (4); 198-202.