Paracetamol Dosing for a 22 kg Child
For a 22 kg child, administer 330 mg of paracetamol (6.6 mL of the 250 mg/5 mL suspension), which can be given every 4-6 hours, not exceeding 5 doses in 24 hours.
Weight-Based Dosing Calculation
- The recommended dose of paracetamol for children is 15 mg/kg per dose to achieve effective antipyretic and analgesic plasma concentrations 1, 2.
- For a 22 kg child: 15 mg/kg × 22 kg = 330 mg per dose 3, 4.
- Using the 250 mg/5 mL formulation: 330 mg ÷ 250 mg × 5 mL = 6.6 mL per dose 5.
Dosing Frequency and Maximum Daily Dose
- Administer every 4-6 hours as needed for fever or pain 5, 6.
- Maximum 5 doses in 24 hours, which equals a total daily dose of 1,650 mg (75 mg/kg/day) 5, 6.
- The maximum safe daily dose is 60-90 mg/kg/day, with the calculated regimen (75 mg/kg/day) falling within this therapeutic range 6, 3.
Clinical Rationale for 15 mg/kg Dosing
- Doses of 10 mg/kg are subtherapeutic and fail to achieve the plasma concentration required for antipyresis (10-20 μg/mL) 1, 2.
- Pharmacokinetic modeling demonstrates that 10 mg/kg produces peak plasma concentrations of only 6.38-8.55 μg/mL, below the therapeutic threshold 2.
- 15 mg/kg dosing achieves plasma concentrations of 9.57-12.8 μg/mL, which is within or approaching the therapeutic range and demonstrates superior clinical efficacy compared to lower doses 1, 2.
- Recent evidence confirms that paracetamol 15 mg/kg is significantly more effective than placebo and at least as effective as NSAIDs for fever and pain management 1.
Safety Considerations
- The calculated dose (330 mg) and daily maximum (1,650 mg) are well below the hepatotoxic threshold of >140 mg/kg/day for chronic use 6.
- Single doses become potentially toxic only at >10 times the recommended dose (>3,300 mg for this child) 6.
- Paracetamol has a tolerability profile similar to placebo when used at 15 mg/kg for short-term treatment, with lower risk of adverse events compared to NSAIDs for consecutive-day use 1.