What is the recommended intravenous (IV) dose of paracetamol (acetaminophen) for a patient weighing 38 kilograms (kg)?

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Intravenous Paracetamol Dosing for 38 kg Patient

For a 38 kg patient, administer 570 mg (15 mg/kg) of IV paracetamol every 4-6 hours, with a maximum daily dose of 2,280 mg (60 mg/kg/day). 1

Weight-Based Dosing Requirements

  • Patients weighing 10-50 kg require weight-adjusted IV paracetamol dosing at 15 mg/kg per dose every 4-6 hours 1
  • The standard 1 gram dose used for adults >50 kg is inappropriate and potentially hepatotoxic for patients under 50 kg 1
  • Maximum daily dose must not exceed 60 mg/kg/day 1

Specific Calculation for 38 kg Patient

  • Single dose: 38 kg × 15 mg/kg = 570 mg per dose 1
  • Maximum daily dose: 38 kg × 60 mg/kg = 2,280 mg per day 1
  • Dosing interval: Every 4-6 hours 1
  • Maximum number of doses: 4 doses per 24 hours if given every 6 hours 1

Critical Safety Considerations

Patient weight must be documented on the drug chart to prevent iatrogenic paracetamol toxicity, which is a potentially life-threatening yet avoidable cause of acute liver failure 1. A quality improvement study demonstrated that failure to adjust IV paracetamol doses for patients <50 kg resulted in 25% of patients receiving inappropriate (excessive) doses 1.

  • Verify actual body weight on admission and document it clearly 1
  • Do not default to the standard 1 gram adult dose for patients under 50 kg 1
  • Monitor for signs of hepatotoxicity, particularly if dosing errors occur 1

Pharmacokinetic Rationale

The 15 mg/kg dosing achieves therapeutic plasma concentrations while maintaining safety margins below toxic thresholds 2. In healthy subjects, a 2-gram starting dose (approximately 26 mg/kg for a 75 kg adult) produced peak concentrations of 67.9 μg/mL without toxicity, demonstrating that weight-based dosing at 15 mg/kg provides adequate analgesia with substantial safety margin 2.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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