What is the maximum recommended dose of paracetamol (acetaminophen) for adults and children?

Maximum Recommended Dose of Paracetamol (Acetaminophen)

For adults, the maximum daily dose of paracetamol is 4000 mg (4 g) per day, with individual doses not exceeding 1000 mg every 4-6 hours, and no more than 6 doses in 24 hours. 1

Adult Dosing

• Standard dose: 650-1000 mg every 4-6 hours as needed 1
• Maximum single dose: 1000 mg 2
• Maximum daily dose: 4000 mg (4 g) in 24 hours 1, 3
• Maximum number of doses: 6 doses per 24-hour period 1

The FDA drug label explicitly warns that severe liver damage may occur if an adult takes more than 6 doses in 24 hours or greater than 4000 mg of acetaminophen. 1

Pediatric Dosing

For children, dosing is weight-based with age-banded alternatives:

Weight-Based Dosing (Preferred)

• Standard dose: 15 mg/kg every 4-6 hours 2
• Maximum daily dose: 75 mg/kg/day (per updated BNF-C guidelines) 4
• Alternative maximum: Some guidelines suggest up to 80 mg/kg/day for acute severe pain, though this exceeds newer recommendations 4
• Absolute maximum: Should not exceed 90 mg/kg/day under any circumstances 5

Age-Banded Dosing (FDA Label) 1

• Ages 12+ years: 650 mg every 4-6 hours (max 6 doses/24h)
• Ages 6-11 years: 325 mg every 4 hours (max 5 doses/24h)
• Ages 4-5 years: 240 mg every 4 hours (max 5 doses/24h)
• Ages 2-3 years: 160 mg every 4 hours (max 5 doses/24h)
• Under 2 years: Consult a doctor 1

Important Pediatric Considerations

• Children under 1 month have no established dosing guidelines 5
• For neonates, limited data suggests 30 mg/kg/day achieves therapeutic concentrations, but further studies are needed 5
• The shift from 90 mg/kg/day to 75 mg/kg/day maximum reflects updated safety data from 2014-2015 4

Critical Safety Warnings

Hepatotoxicity Risk

Severe liver damage can occur when: 1

• Total daily dose exceeds 4000 mg in adults
• Paracetamol is combined with other acetaminophen-containing products
• Used with 3 or more alcoholic drinks daily
• Used in patients with pre-existing liver disease

Overdose Thresholds Requiring Emergency Evaluation 6

Patients should be referred to the emergency department if ingestion is:

• ≥200 mg/kg or 10 g (whichever is less) within 24 hours
• ≥150 mg/kg/24h or 6 g/day (whichever is less) within 48 hours
• ≥100 mg/kg/24h or 4 g/day (whichever is less) for more than 48 hours

Repeated Supratherapeutic Ingestions

Doses exceeding 4 g per day over multiple days can result in hepatotoxicity, hepatic failure, and death, even without a single acute overdose. 7 Treatment with N-acetylcysteine is recommended for serum acetaminophen concentrations ≥10 mg/mL or elevated aminotransferases (AST or ALT >50 IU/L). 7

Special Populations

Elderly Patients

• No routine dose reduction is necessary for older adults with normal organ function 3
• The standard maximum of 4000 mg/day applies 3
• Dosing should be individualized only for those with decompensated cirrhosis or advanced kidney failure 3

Patients with Comorbidities

• Liver disease: Contraindicated in hepatic insufficiency; use with extreme caution in chronic benign liver disease 2
• Renal insufficiency: Usually no dose adjustment needed, though clearance is reduced 2
• Pregnancy/lactation: Can be used safely 2

Common Pitfalls to Avoid

1. Hidden acetaminophen: Many combination products (especially opioid combinations) contain acetaminophen—always verify total daily intake from all sources 1
2. Dosing confusion: Different manufacturers now recommend different maximum doses (3000 mg for some 500 mg tablet products vs. 3900 mg for 650 mg arthritis products), creating confusion 8
3. Pediatric calculation errors: Always use weight-based dosing when possible rather than age-banding to ensure accuracy 4
4. Chronic use: Repeated daily use at maximum doses increases risk of cumulative toxicity 7, 5