Maximum Pediatric Acetaminophen Dose
The maximum recommended acetaminophen dose for children is 15 mg/kg per dose (not to exceed 75 mg/kg/day or 4 grams/day total), given every 4-6 hours, with an absolute maximum of 60 mg/kg per day or 5 doses in 24 hours. 1
Per-Kilogram Dosing
- Standard single dose: 10-15 mg/kg per dose 1, 2
- Dosing interval: Every 4-6 hours 1, 3
- Maximum daily dose: 60 mg/kg/day 1, 2
- Maximum number of doses: 5 doses in 24 hours 1
The 10-15 mg/kg range provides flexibility based on pain/fever severity, with 15 mg/kg being more effective than 10 mg/kg for sustained temperature reduction over 6 hours 4. For infants under 3 months, acetaminophen is the only recommended analgesic, with a dose of 15 mg/kg if weight is less than 10 kg 1.
Absolute Maximum Limits
Critical safety thresholds that should never be exceeded:
- Daily maximum: 60 mg/kg/day 1, 2
- Frequency maximum: 5 doses in 24 hours 1
- Adult maximum (children >40 kg): 4 grams/day 5
These limits exist because single ingestions exceeding ten times the recommended dose are potentially hepatotoxic 2, and chronic exposures greater than 140 mg/kg/day for several days carry risk of serious liver toxicity 2.
Risk-Adjusted Dosing (Reduced to 10 mg/kg)
Reduce the dose to 10 mg/kg per dose in these high-risk situations:
- Children with chronic malnutrition or fasting >8 hours without adequate caloric intake 1
- Children receiving cytochrome P450-inducing medications (e.g., isoniazid) 1
- Children with pre-existing liver disease 1
These conditions increase hepatotoxicity risk by raising production of the toxic NAPQI metabolite or reducing hepatic reserve 1.
Route-Specific Considerations
- Oral syrup/suspension (preferred): Absorbed more rapidly and provides more consistent response than suppositories 1, 4
- Rectal suppositories: Should be used cautiously due to erratic absorption; some children may receive inadequate analgesia while others risk accumulation with repeated dosing 1
The oral route is preferred for reliability, with rectal administration reserved for children actively vomiting or in perioperative situations where oral intake is restricted 1.
Common Pitfalls to Avoid
- Never exceed 60 mg/kg/day or 5 doses in 24 hours under any circumstances 1
- Do not use weight-based dosing for children >40 kg—switch to adult dosing with a 4-gram daily maximum 5
- Avoid underdosing: 27% of parents in one study gave less than 10 mg/kg per dose, which provides inadequate fever control 6
- Watch for "hidden" acetaminophen in combination over-the-counter medications to prevent inadvertent overdose 1