IV Paracetamol Dosage for a 20kg Child
For a 20kg child with normal renal and liver function, administer 15 mg/kg per dose IV every 6 hours, which equals 300 mg per dose, with a maximum daily dose of 60 mg/kg/day (1200 mg/day). 1
Weight-Based Dosing Calculation
- Single dose: 15 mg/kg × 20 kg = 300 mg per dose 1
- Frequency: Every 4-6 hours 1
- Maximum daily dose: 60 mg/kg/day × 20 kg = 1200 mg/day 1
- Maximum number of doses: 4 doses per 24 hours 2
Preparation and Administration
- Standard concentration: IV paracetamol comes as 10 mg/mL 3
- Volume to administer: 300 mg ÷ 10 mg/mL = 30 mL per dose 3
- Dilution: Can be diluted in 0.9% normal saline or 5% dextrose if needed 3
- Infusion time: Administer over 15 minutes (standard practice for IV paracetamol, though not explicitly stated in provided evidence)
Dosing Interval Considerations
- The every 6 hours interval is preferred over every 4 hours to maintain safety margins and prevent cumulative toxicity 1, 2
- If dosing every 4 hours, ensure total daily dose does not exceed 60 mg/kg/day (1200 mg) 1
- Never exceed 5 doses in 24 hours 1
Critical Safety Points
- Hepatotoxicity risk: Single ingestions exceeding 10 times the recommended dose (>150 mg/kg) are potentially toxic 2
- Chronic overdose threshold: Exposures greater than 140 mg/kg/day for several days carry risk of serious liver toxicity 2
- For this 20kg child: Stay well below 2800 mg/day (140 mg/kg/day threshold) 2
Route Comparison
- IV route advantages: More predictable absorption compared to rectal administration, which has erratic absorption 1, 4
- Oral route: If the child can tolerate oral intake, oral syrup is absorbed more rapidly and provides more consistent response than suppositories 1
Clinical Context
- Paracetamol is effective for mild to moderate pain and provides significant additive analgesic effect when combined with opiates for severe pain 2
- For children with stable neurologic conditions, paracetamol is generally safe and preferred over NSAIDs 1
- The pharmacokinetics are linear at therapeutic concentrations, meaning the dose-response relationship is predictable 4