Perfalgan Dosing for a 36 kg Child
For a child weighing 36 kg, administer Perfalgan (intravenous paracetamol) 500 mg per dose, given every 4-6 hours, with a maximum of 2000 mg (2 g) per 24 hours.
Weight-Based Dosing Calculation
- The standard pediatric dose of paracetamol is 15 mg/kg per dose 1, 2, 3, 4
- For a 36 kg child: 15 mg/kg × 36 kg = 540 mg per dose
- In clinical practice, this rounds to 500 mg per dose for ease of administration 2
Dosing Interval and Maximum Daily Dose
- Administer every 4-6 hours as needed 5, 1, 3
- Maximum of 4 doses in 24 hours 5, 1
- Maximum daily dose: 60 mg/kg/day 1, 3
- For 36 kg: 60 mg/kg × 36 kg = 2160 mg/day maximum
- Practical maximum: 2000 mg per 24 hours (4 doses of 500 mg) 5
Critical Safety Considerations
- Never exceed 90-95 mg/kg/day as this threshold is associated with cumulative hepatotoxicity risk 6
- For a 36 kg child, this absolute safety limit would be approximately 3240 mg/day, but the recommended maximum remains 2000-2160 mg/day 1, 3, 6
Common Prescribing Pitfall
- Studies show that 17% of paracetamol prescriptions exceed safe dosing limits, though most are caught before administration 6
- Always calculate and document each dose time to prevent inadvertent overdosing, especially if multiple caregivers are involved 4
Clinical Context
- Perfalgan (IV paracetamol) follows the same weight-based dosing principles as oral paracetamol 1, 2, 3
- The 15 mg/kg dose provides optimal analgesic and antipyretic efficacy while maintaining safety 1, 2, 3
- Therapeutic effect typically lasts 4-6 hours, though analgesic activity may decline after 6 hours 3