Paracetamol Dosing for 10-Year-Old Child
Give 735 mg (15 mg/kg) of paracetamol now, which can be administered as two 325 mg tablets plus half of another 325 mg tablet, or approximately 12.5 mL of standard liquid formulation (32 mg/mL). Since 4 hours have elapsed since the previous dose, it is safe to administer the next dose.
Dosing Rationale
For this 49 kg child:
- Weight-based dosing: 15 mg/kg × 49 kg = 735 mg per dose 1, 2
- Dosing interval: Every 4-6 hours 3
- Maximum daily doses: Not to exceed 5 doses in 24 hours for children 3
- Maximum daily amount: Should not exceed 60-75 mg/kg/day (approximately 2,940-3,675 mg/day for this child) 1, 4
The previous dose of 325 mg was subtherapeutic for this child's weight. Research demonstrates that paracetamol doses of ≤10 mg/kg are generally less effective than appropriate dosing, while 15 mg/kg provides optimal antipyretic and analgesic efficacy with maximum temperature reduction occurring approximately 3 hours post-administration 1, 2.
Practical Administration Options
Since exact dosing may be challenging with 325 mg tablets:
- Option 1: Give 2 tablets (650 mg) - this provides 13.3 mg/kg, which is within the therapeutic range of 10-15 mg/kg 1
- Option 2: Give 2.25 tablets (731 mg) if tablets can be split - this provides the ideal 15 mg/kg dose
- Option 3: Use liquid formulation if available for more precise dosing
Safety Considerations
Critical thresholds to avoid toxicity 5:
- Single dose should not exceed 1 gram (1000 mg) for this child
- Daily intake should not exceed 60 mg/kg/day for prolonged use (2,940 mg/day for 49 kg)
- Repeated supratherapeutic dosing (>150 mg/kg/24h for 48h or >100 mg/kg/24h for >48h) carries risk of hepatotoxicity 6, 5
With the previous 325 mg dose 4 hours ago and the recommended 650-735 mg now, the child will have received approximately 975-1,060 mg in 4 hours, which is well below toxic thresholds.
Monitoring and Follow-up
- Continue dosing every 4-6 hours as needed for fever/discomfort
- Do not exceed 5 doses in 24 hours 3
- Document all dose times carefully to prevent accidental overdosing 7
- If fever persists beyond 3 days or worsens, seek medical evaluation 3
- The fever of 102°F (38.9°C) should begin to decrease within 1-3 hours of proper dosing 1
Common Pitfall
The most significant error in this scenario is underdosing based on available tablet strength rather than the child's weight. A 325 mg dose provides only 6.6 mg/kg for this 49 kg child, which is subtherapeutic and explains why fever control may be inadequate 1, 2.