What is the recommended dose of paracetamol (acetaminophen) for a 25kg pediatric patient using the 250mg/5ml preparation?

Paracetamol Dosing for a 25kg Child Using 250mg/5mL Preparation

For a 25kg pediatric patient, administer 10mL (500mg) of the 250mg/5mL paracetamol preparation every 4-6 hours, not exceeding 5 doses in 24 hours, based on the standard 15-20mg/kg per dose recommendation.

Weight-Based Dosing Calculation

• The optimal single dose range for paracetamol in children is 10-15 mg/kg per dose, administered every 4-6 hours 1, 2
• For a 25kg child, this translates to 250-375mg per dose 1
• Using the 250mg/5mL preparation (50mg/mL concentration), a 15mg/kg dose equals 375mg, which is 7.5mL 1
• A practical and effective dose would be 10mL (500mg or 20mg/kg), which falls within the safe and effective range 3

Dosing Frequency and Maximum Daily Dose

• Administer every 4-6 hours as needed, not exceeding 5 doses in 24 hours 4
• The maximum daily dose should not exceed 75-90 mg/kg/day 2, 5
• For a 25kg child, this means a maximum of 1,875-2,250mg per day 2
• Five doses of 10mL (500mg each) equals 2,500mg daily, which approaches but does not exceed the upper safety limit when spaced appropriately 5

Critical Safety Considerations

• Doses below 10mg/kg often fail to achieve therapeutic plasma concentrations (10-20 μg/mL) needed for effective antipyresis 6
• The commonly recommended 160mg dose for children in this weight range is inadequate, as pharmacokinetic modeling shows it produces subtherapeutic plasma levels 6
• Weight-based dosing is superior to age-based dosing for ensuring therapeutic efficacy and avoiding both underdosing and overdosing 1, 6

Common Pitfalls to Avoid

• Do not use age-based dosing alone, as up to 30% of children receive inadequate doses when age rather than weight guides dosing 6
• Avoid the 10mg/kg dose as it consistently fails to reach therapeutic plasma concentrations 6
• Chronic overdosing (>140 mg/kg/day for several days) carries risk of hepatotoxicity, even though single doses up to 150mg/kg are generally well-tolerated 2
• Monitor cumulative daily doses carefully, as 17% of prescriptions in hospital settings exceed 95 mg/kg/day due to calculation errors 5

Practical Administration

• Measure doses using an accurate oral syringe or dosing cup marked in milliliters 4
• For a 25kg child using 250mg/5mL preparation: give 7.5-10mL per dose (375-500mg) 1, 3
• Space doses at minimum 4-hour intervals, with 6-hour intervals preferred for routine use 4, 2