When to administer intravenous (IV) versus oral (PO) paracetamol (acetaminophen) to infants?

Administration of Paracetamol (Acetaminophen) in Infants

The route of paracetamol administration in infants should be based on clinical setting, with oral administration preferred whenever possible and intravenous administration reserved for postoperative settings or when oral route is not feasible. 1

Route Selection Guidelines

Oral (PO) Administration - First Line

• Oral paracetamol should be used as first-line therapy for mild to moderate pain and fever management in infants who can tolerate oral medications 2
• Recommended oral dosing is 15 mg/kg every 4-6 hours (maximum 60 mg/kg/day) to achieve adequate analgesic and antipyretic effects 3
• Aim for oral administration as soon as possible in postoperative settings to minimize invasive interventions 1
• Oral paracetamol shows similar efficacy to NSAIDs when used at appropriate dosages (15 mg/kg) for pain and fever management 2

Intravenous (IV) Administration - Specific Indications

• IV paracetamol is indicated in postoperative settings, particularly in the PACU (Post-Anesthesia Care Unit) and during the immediate postoperative period 1
• IV paracetamol should be used when the oral route is not feasible due to:
  • NPO (nil per os) status 1
  • Inability to tolerate oral medications 1
  • Need for rapid onset of analgesia 1
• For term neonates (>32 weeks gestational age), recommended IV dosing is a loading dose of 20 mg/kg followed by 10 mg/kg every 6 hours 4
• For preterm neonates (<32 weeks), a reduced dosing of 12 mg/kg loading dose followed by 6 mg/kg every 6 hours is suggested 4

Rectal Administration - Alternative Route

• Rectal paracetamol can be used when both oral and IV routes are unavailable 1
• Rectal administration is particularly useful in the immediate postoperative period when oral intake is not yet established 1
• Absorption via the rectal route is slower and more irregular compared to oral or IV administration 3
• Rectal paracetamol is recommended at basic and intermediate levels of pain management according to the ESPA Pain Management Ladder 1

Clinical Setting-Based Recommendations

Postoperative Pain Management

• For basic level postoperative care: Use rectal paracetamol in combination with local anesthetics 1
• For intermediate level care: Use rectal or IV paracetamol, transitioning to oral as soon as possible 1
• For advanced level care: IV paracetamol during PACU stay, transitioning to oral in the ward 1
• Combine paracetamol with NSAIDs when possible to reduce opioid requirements 1

Fever Management

• Oral paracetamol at 15 mg/kg is effective for fever reduction in infants 2, 5
• IV paracetamol should be reserved for cases where rapid temperature reduction is needed and oral route is not available 3, 6

Important Considerations and Monitoring

• Ensure adequate monitoring (pulse oximetry and/or clinical observation) when using IV paracetamol in infants, particularly in postoperative settings 1
• Carefully record all dose times when using multiple analgesics to avoid accidentally exceeding maximum recommended doses 5
• Be aware that approximately 8% of children may inadvertently receive doses exceeding the recommended maximum 5
• For infants undergoing procedures like circumcision, consider paracetamol as part of a multimodal approach rather than as sole therapy 7
• IV paracetamol has not been licensed for analgesia in preterm neonates in Europe or infants <2 years in the United States, so its use is off-label in these populations 4, 6

Common Pitfalls to Avoid

• Avoid subtherapeutic dosing (<10 mg/kg), which has been shown to be less effective than appropriate dosing (15 mg/kg) 2, 3
• Do not delay transition from IV to oral paracetamol once the oral route is available 1
• Avoid prolonged IV administration when oral route is feasible, as this increases costs without providing additional benefits 5, 6
• Be cautious with dosing in extremely preterm neonates, as pharmacokinetic data is limited in this population 4, 6