Acetaminophen Dosing for 6kg Infant
For a 6kg infant, administer 60-90 mg of acetaminophen liquid (oral suspension) per dose, given every 4-6 hours as needed, not exceeding 5 doses in 24 hours.
Weight-Based Dosing Calculation
- The standard recommended dose is 10-15 mg/kg per dose for infants and children 1, 2.
- For a 6kg infant, this translates to:
- Minimum dose: 60 mg (10 mg/kg × 6 kg)
- Maximum dose: 90 mg (15 mg/kg × 6 kg)
- Doses should be administered every 4-6 hours as needed, with a maximum of 5 doses per 24-hour period 1.
Optimal Dosing Strategy
- The 15 mg/kg dose (90 mg for 6kg infant) is more effective than 10 mg/kg and provides better antipyretic effect, maintaining temperature reduction for approximately 6 hours 3, 2.
- The 10 mg/kg dose may not achieve adequate plasma concentrations (10-20 μg/mL) required for optimal antipyresis, whereas 15 mg/kg consistently reaches therapeutic levels 4.
- Peak temperature reduction occurs approximately 3 hours after administration 2.
Liquid Formulation Considerations
- Common acetaminophen liquid suspensions contain 160 mg per 5 mL (32 mg/mL concentration).
- For a 6kg infant using 15 mg/kg dosing:
- 90 mg = approximately 2.8 mL of standard suspension
- For 10 mg/kg dosing: 60 mg = approximately 1.9 mL
- Oral suspension provides more consistent absorption and response compared to suppositories 3.
Critical Safety Points
- Never exceed 75 mg/kg per 24 hours total daily dose 1.
- For a 6kg infant, maximum daily dose = 450 mg (five 90mg doses).
- Underdosing is common—studies show 27% of children receive inadequate doses (<10 mg/kg), resulting in poor fever control 5.
- Use weight-based dosing rather than age-based recommendations to ensure accuracy, as age-based dosing leads to frequent errors 4.