What is the recommended dose of Tylenol (acetaminophen) for an 18-month-old child weighing 10.6kg?

Acetaminophen Dosing for an 18-Month-Old Weighing 10.6kg

For an 18-month-old child weighing 10.6kg, administer acetaminophen at 10-15 mg/kg per dose every 4-6 hours as needed, which translates to 106-159 mg per dose (round to 110-160 mg practically), with a maximum of 5 doses in 24 hours and not exceeding 75 mg/kg/day (approximately 800 mg/day for this child). 1

Weight-Based Dosing Calculation

• The standard pediatric dosing is 10-15 mg/kg per dose, which for a 10.6 kg child equals:

  • Minimum dose: 10 mg/kg × 10.6 kg = 106 mg per dose 1
  • Maximum dose: 15 mg/kg × 10.6 kg = 159 mg per dose 1

• Practical dosing using available formulations:

  • If using infant drops (80 mg/0.8 mL or 160 mg/5 mL concentration): give approximately 1.25-2 mL per dose 1
  • If using children's suspension (160 mg/5 mL): give approximately 3.5-5 mL per dose 1

Maximum Daily Dose Limits

• The maximum daily dose is 75 mg/kg/day, which equals approximately 795 mg/day for this 10.6 kg child (round to 800 mg/day maximum) 1
• This translates to no more than 5 doses in 24 hours when using the 10-15 mg/kg dosing range 1
• Maintain at least 4-6 hours between doses to prevent accumulation 1, 2

Administration Guidelines

• Use an oral syringe or calibrated measuring device to ensure accurate dosing—never use household spoons 1
• Acetaminophen can be given with or without food, though administration with food may reduce gastrointestinal upset 1
• Do not exceed 5 doses in 24 hours regardless of symptom persistence 1

Critical Safety Considerations

• Hepatotoxicity risk begins when plasma concentrations exceed 150 micrograms/mL, which is far above therapeutic levels (5-20 micrograms/mL) but can occur with overdosing 2
• Long-term therapeutic use at recommended doses does not cause liver damage, but repeated supratherapeutic dosing is a concern 2, 3
• Check all other medications the child is receiving to avoid duplicate acetaminophen exposure from combination products 4

Common Pitfalls to Avoid

• Never use adult formulations or adult dosing for pediatric patients—the adult maximum of 3000-4000 mg/day does not apply to children 4
• Avoid confusion between different concentrations of liquid acetaminophen (infant drops vs. children's suspension have different concentrations) 1
• Do not dose more frequently than every 4 hours as this increases toxicity risk without improving efficacy 1, 2
• If fever or pain persists beyond 3-5 days of appropriate acetaminophen use, medical re-evaluation is necessary rather than continued dosing 1