What is the recommended dose of acyclovir for pediatric patients?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: February 19, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

The recommended dose of acyclovir for pediatric patients is 20 mg/kg IV every 8 hours for 14-21 days for neonates with herpes simplex virus (HSV) infection 1.

Dosing by Age and Indication

  • For neonates (0-3 months) with HSV infection, the dose is 20 mg/kg IV every 8 hours for 14-21 days 1.
  • For infants (3-12 months) and children (1-12 years) with severe HSV infections, the dose is 10-20 mg/kg IV every 8 hours for 7-14 days.
  • For children with varicella (chickenpox), the dose is 20 mg/kg orally 4 times a day for 7-10 days, with a maximum dose of 800 mg 4 times a day 1.
  • For children with HSV encephalitis, the dose is 10-20 mg/kg IV every 8 hours for 14-21 days.
  • For children with immunocompromised status, the dose and duration may need to be adjusted based on clinical response and viral load. It's essential to consult with a pediatrician or a healthcare professional for specific guidance on dosing and treatment duration.

From the FDA Drug Label

Pediatrics Acyclovir pharmacokinetics were determined in 16 pediatric patients with normal renal function ranging in age from 3 months to 16 years at doses of approximately 10 mg/kg and 20 mg/kg every 8 hours Acyclovir pharmacokinetics were determined in 12 patients ranging in age from birth to 3 months at doses of 5 mg/kg, 10 mg/kg, and 15 mg/kg every 8 hours

The recommended dose of acyclovir for pediatric patients is:

  • For patients from 3 months to 16 years: approximately 10 mg/kg and 20 mg/kg every 8 hours
  • For patients from birth to 3 months: 5 mg/kg, 10 mg/kg, and 15 mg/kg every 8 hours 2

From the Research

Recommended Dose of Acyclovir for Pediatric Patients

The recommended dose of acyclovir for pediatric patients varies depending on the age and weight of the patient, as well as the specific infection being treated.

  • For neonates (younger than 1 month of age), a dose of 24 mg/kg of body weight three times a day is recommended 3.
  • For infants older than 1 month of age, a dose of 24 mg/kg of body weight four times a day is recommended 3.
  • For the treatment of herpes simplex virus (HSV) infections, a dose of 10 mg/kg of body weight every 6 hours for children with normal renal function is recommended 4.
  • For the treatment of varicella-zoster virus (VZV) infections, a twofold increase in the dose may be necessary for children older than 3 months of age 3.
  • High-dose acyclovir (60 mg/kg/d) is recommended for the treatment of neonatal herpes simplex virus infections, although this dose is not currently approved by the US Food and Drug Administration 5.

Factors Affecting Acyclovir Dosing

Several factors can affect the dosing of acyclovir in pediatric patients, including:

  • Age: The pharmacokinetics of acyclovir change significantly during the first month of life, with the elimination half-life decreasing from 10-15 hours to 2.5 hours 3.
  • Weight: Dosage adjustment by body weight is recommended for pediatric patients 3.
  • Renal function: The estimated glomerular filtration rate (eGFR) is significantly associated with acyclovir elimination, and dosing may need to be adjusted for patients with impaired renal function 4.

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.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.