A 3.0 kg neonate is prescribed acyclovir. What is the recommended dose per kilogram given every 8 hours?

• A. 10 mg/kg/dose every 8 hours
• B. 20 mg/kg/dose every 8 hours
• C. 30 mg/kg/dose every 8 hours
• D. 40 mg/kg/dose every 8 hours

Answer: (B)

Dosing in neonates is weight-based and given at regular intervals to achieve about 60 mg/kg per day, balancing effective antiviral exposure with the neonate’s immature renal clearance. For a neonate weighing 3 kg, the per‑dose amount is 20 mg/kg × 3 kg = 60 mg per dose. Administered every 8 hours, this totals 180 mg per day (60 mg/kg/day). This schedule maintains therapeutic drug levels while reducing the risk of accumulation. In practice, monitor renal function and hydration, as dose adjustments may be needed if renal activity is reduced.