Paracetamol Minimum Concentration for Dilution
The smallest concentration dilution of paracetamol for pediatric or sensitive patients is 10 mg/mL, which is the standard commercial preparation that can be further diluted in 0.9% normal saline or 5% dextrose for neonates requiring smaller volumes. 1
Standard Preparation and Dilution
The commercial intravenous paracetamol preparation comes as 10 mg/mL, which serves as the baseline concentration for all pediatric dosing 1
This 10 mg/mL solution can be diluted in 0.9% normal saline (NS) or 5% dextrose (D5W) when smaller volumes are needed for neonates or very young infants 1
For example, a 7.5 mg/kg dose for a 5 kg infant equals 37.5 mg total, which translates to 3.75 mL of the 10 mg/mL solution 1
Practical Dosing Considerations
Oral formulations contain 160 mg per 5 mL (32 mg/mL), which is a higher concentration than IV preparations 2
Age-Specific Dosing from FDA Label:
- Children 2 to under 4 years: 5 mL (160 mg) every 4 hours, not exceeding 5 doses in 24 hours 2
- Children 4 to under 6 years: 7.5 mL (240 mg) every 4 hours, not exceeding 5 doses in 24 hours 2
- Children under 2 years: Consult a physician for appropriate dosing 2
Intravenous Dosing Guidelines
Loading dose for IV paracetamol is 15-20 mg/kg, followed by maintenance doses of 10-15 mg/kg every 6-8 hours 3
The European Society for Paediatric Anaesthesiology recommends these doses using the 10 mg/mL preparation 3
Maximum daily dose should not exceed 60 mg/kg/day in pediatric patients 4, 5
Critical Safety Considerations
Avoid cumulative toxicity by never exceeding 90-95 mg/kg/day, as doses above this threshold carry risk of hepatic and renal damage 6
Single ingestions exceeding ten times the recommended dose are potentially hepatotoxic 5
Chronic overdosing (>140 mg/kg/day for several days) carries significant risk of serious toxicity and liver failure 5
Special Populations:
Neonates under 2 weeks: Limited data exists; 30 mg/kg/day achieves therapeutic concentrations but requires further study 6
Infants 1-3 months: Literature suggests 60-65 mg/kg/day, though pharmacokinetic data may favor higher doses 6
Infants have prolonged elimination half-lives (55-90 hours vs. 30 hours in adults), necessitating careful weight-based dosing rather than extrapolating adult doses 7
Common Pitfalls to Avoid
Do not use weight-based dosing recommendations for term infants in premature infants due to immature renal function and risk of drug accumulation 7
Approximately 50% of infants may require doses higher than initial recommendations to achieve adequate therapeutic effect, requiring dose titration based on clinical response 7
The 10 mg/mL IV concentration should never be confused with the more concentrated oral formulation (32 mg/mL) to prevent dosing errors 1, 2