Paracetamol Dosing for a 9-Year-Old Weighing 35 kg
For a 9-year-old child weighing 35 kg, administer paracetamol 525 mg (15 mg/kg) every 4-6 hours as needed, not exceeding 2100 mg (60 mg/kg) in 24 hours. 1
Weight-Based Dosing Calculation
- The standard dose is 10-15 mg/kg per dose, given every 4-6 hours 1
- For optimal efficacy, use 15 mg/kg rather than 10 mg/kg, as recent evidence demonstrates that 15 mg/kg is significantly more effective than placebo and at least as effective as NSAIDs for fever and pain management 2
- For this 35 kg child: 15 mg/kg × 35 kg = 525 mg per dose 1
- Maximum daily dose: 60 mg/kg/day (35 kg × 60 mg/kg = 2100 mg/day maximum) 1, 3
- Do not exceed 5 doses in 24 hours 1
Practical Dosing Options
Since 525 mg is not a standard tablet size, choose one of these approaches:
- 500 mg per dose (14.3 mg/kg) - slightly below optimal but acceptable and uses standard tablet strength 4
- Two 250 mg tablets = 500 mg per dose 4
- Liquid formulation: If using oral suspension, calculate exact 525 mg dose for precision 1
Dosing Interval
- Administer every 4-6 hours as needed 1, 4
- The analgesic effect typically lasts 4-6 hours, with decline in activity usually occurring after 6 hours 4
- When alternating with ibuprofen (if needed), give paracetamol every 4-6 hours and ibuprofen every 6-8 hours, staggering timing so medications are given every 3-4 hours 1
Route of Administration
- Oral route is strongly preferred over rectal administration 1
- Oral syrup formulation is absorbed more rapidly and provides more consistent response compared to suppositories 1
- Effervescent tablets provide more rapid absorption and onset of action than conventional tablets 4
Safety Considerations
- Never exceed 60 mg/kg per day or 5 doses in 24 hours to prevent hepatotoxicity 1, 3
- Single ingestions exceeding ten times the recommended dose are potentially toxic 3
- Chronic exposures greater than 140 mg/kg/day for several days carry risk of serious liver toxicity 3
- At therapeutic doses, paracetamol has a tolerability profile similar to placebo and shows lower risk of adverse events compared to NSAIDs when used repetitively for consecutive days 2
Clinical Context
- Paracetamol is considered first-line therapy for mild-to-moderate pain and fever in children according to international guidelines 2
- Unlike NSAIDs, paracetamol is indicated for use in children of all ages 2
- For post-vaccination fever, paracetamol can be given at time of vaccination and every 4 hours for 24 hours 1
- Paracetamol will improve comfort but does not prevent febrile seizures, even when given prophylactically 1