Paracetamol

Question 1

Presentation

Answer 1

500 mg tablets

120 mg in 5 mL oral liquid (24 mg/mL)

Question 2

Pharmacology

Answer 2

An analgesic and antipyretic agent

Question 3

Pharmacology - Actions

Answer 3

Exact mechanism of action unclear;

Thought to inhibit prostaglandin synthesis in the CNS

Question 4

Metabolism

Answer 4

Metabolised = liver
Excreted = kidneys

Question 5

Indications

Answer 5

Mild pain

Headache

Question 6

Contras

Answer 6

Hypersensitivity to paracetamol
Children < 1 month old
Previous administration within past 4 hrs
Total intake in 24 hrs exceeding 4g (adults) or 60 mg/kg (children)
Chest pain in suspected acute coronary syndrome

Question 7

Precautions

Answer 7

Impaired hepatic function or liver disease
Elderly / frail
Malnourished

Question 8

Route of administration

Answer 8

Oral

Question 9

Side effects

Answer 9

Hypersensitivity reactions including severe skin rashes (rare)
Haematological reactions (rare)

Question 10

Special Notes

Answer 10

There are several brands of paracetamol available, carefully check previous intake before dose administration.

Usual dose for children is 15 mg/kg per dose. Max total dose is 60 mg/kg which equates to 4 doses within 24 hrs.

Hepatic damage is very rare when taken as recommended.

Not indicated for Rx of fever in the emergency setting.

Question 11

Oral effects

Answer 11

Onset = 30 mins
Peak = N/A
Duration = 4 hrs

Question 12

Moderate Pain relief

Answer 12

Consider administering paracetamol in addition to opioids for moderate pain where the oral route is not contraindicated (eg: possible emergency surgery or procedural sedation).

Question 13

Mild Pain - Adult

Answer 13

1000 mg oral

Question 14

Mild Pain - < 60 kg/frail/elderly/malnourished/liver disease

Answer 14

500 mg oral

Question 15

Mild Pain - Peadiatric

Answer 15

15 mg/kg liquid

Children aged 10-11 yrs can have a single 500 mg tablet as an alternative to the liquid preparation depending on pt preference.