Paracetamol (Acetaminophen) Dosing for Children
For children 4 months and older, use 10-15 mg/kg per dose every 4-6 hours, not exceeding 60-75 mg/kg/day or 5 doses in 24 hours. 1, 2, 3, 4, 5
Standard Dosing by Age and Weight
Oral Dosing Guidelines
Children 2 to under 4 years:
- 5 mL (160 mg) every 4 hours
- Maximum 5 doses in 24 hours 3
Children 4 to under 6 years:
- 7.5 mL (240 mg) every 4 hours
- Maximum 5 doses in 24 hours 3
Children 6 to under 12 years:
- 10.15 mL (325 mg) every 4 hours
- Maximum 5 doses in 24 hours 3
Children 12 years and older:
- 20.3 mL (650 mg) every 4-6 hours
- Maximum 6 doses in 24 hours 3
Weight-Based Dosing Algorithm
For precise dosing in all pediatric patients 4 months and older:
- Single dose: 10-15 mg/kg 6, 5
- Dosing interval: Every 4-6 hours 4, 5
- Maximum daily dose: 60-75 mg/kg/day (not to exceed 4 grams/day in adolescents) 4, 5
- Maximum frequency: 4-5 doses per 24 hours 3, 4
The 15 mg/kg dose every 4 hours (up to 60 mg/kg/day total) is commonly used in Australia and provides optimal analgesic and antipyretic effect 5. The UK uses 10 mg/kg every 4 hours up to 4 doses daily 4.
Special Populations
Infants Under 4 Months
For term infants 1-3 months:
- 3 mg/kg per dose twice daily 2
- Literature suggests 60-65 mg/kg/day is safe, though pharmacokinetic data may support higher doses 7
For neonates under 2 weeks:
- 30 mg/kg/day achieves therapeutic concentrations 7
- Do not extrapolate weight-based dosing from older infants due to immature renal function and prolonged elimination half-life (55-90 hours vs. 30 hours in adults) 2
For children under 2 years (general):
- Consult a physician for specific dosing 3
Hepatic Impairment
Reduce doses and extend dosing intervals to minimize hepatotoxicity risk 1, 2. Paracetamol is contraindicated in hepatic insufficiency 5.
Renal Impairment
Standard dosing can generally be used, but monitor for drug accumulation 1. No dose reduction is typically necessary even with reduced clearance 5.
Administration Technique
Use precise measuring devices:
- 3-mL or 5-mL oral syringes for infants and young children 1, 2, 8
- This prevents dosing errors that commonly occur with household spoons or imprecise measuring tools 2
Safety and Toxicity Prevention
Acute Overdose Thresholds
Single ingestions exceeding 10 times the recommended dose are potentially hepatotoxic 4.
Chronic Overdose Risk
Chronic exposures greater than 140 mg/kg/day for several days carry serious risk of liver toxicity and failure 1, 4. Even doses exceeding 90-95 mg/kg/day can cause cumulative hepatic and renal toxicity 7.
Combination Products
Exercise caution with opioid-acetaminophen combination products to prevent excess paracetamol dosing 1, 2. The FDA has limited paracetamol content in prescription combination products to 325 mg per dosage unit 1, 2.
Clinical Efficacy Considerations
If paracetamol is ineffective for fever or pain management, consider ibuprofen as second-line treatment 1, 2, 8. Paracetamol has equivalent efficacy to other analgesic-antipyretics in clinical studies and remains the first-choice over-the-counter treatment for analgesia and antipyresis in children 4, 6.
Common Prescribing Pitfalls
Many dosing schedules recommend inadequate amounts of paracetamol 6. In one hospital audit, 17% of prescriptions exceeded 95 mg/kg/day, though only 3% of children actually received these excessive doses due to pharmacy and nursing oversight 7. Medical staff are frequently unsure of safe dosing regimens, particularly for younger age groups 7.
Key pitfall: Prescribing "as needed" without clear maximum daily limits can lead to cumulative toxicity over multiple days 7.