An 8-week-old baby develops fever after MenB vaccination. The parent asks how to bring the temperature down. What is the most appropriate dosing instruction?

• A. Paracetamol 120 mg/5 mL, 2.5 mL every 4–6 hours, maximum 3 doses in 24 hours
• B. Ibuprofen 100 mg every 6 hours as needed
• C. Paracetamol 60 mg/5 mL, 1 mL every 4 hours, maximum 4 doses in 24 hours
• D. Give alternating paracetamol and ibuprofen every 4 hours

Answer: (A)

Fever in a very young baby is best treated with paracetamol given at weight-based, small doses every 4–6 hours, with a safe limit for total daily dosing. The 120 mg/5 mL formulation dosed as 2.5 mL provides about 60 mg per dose, which is roughly 15 mg/kg for a typical 3–4 kg infant, and giving it up to three times in 24 hours keeps the daily amount within safe limits. This approach uses an appropriate, effective dose for fever while minimizing the risk of overdose.

Ibuprofen is not appropriate for an 8-week-old, as it’s generally avoided before 6 months. Alternating paracetamol and ibuprofen adds dosing complexity and a higher risk of error, and the very low dose in option C would not adequately reduce fever.