Acyclovir Dosing for Genital Herpes in Children
Weight-Based Dosing Algorithm
- The Centers for Disease Control and Prevention (CDC) recommends acyclovir 20 mg/kg per dose (maximum 400 mg/dose) orally three times daily for 5-14 days for children with genital herpes weighing less than 45 kg 1, 2
- The CDC guidelines specify a treatment duration of 5-14 days, with the specific duration determined by disease severity 1, 2
- For adolescents ≥45 kg and adults, the CDC recommends acyclovir 400 mg orally twice daily for 5-14 days 1, 2
Critical Implementation Points
- The American Academy of Pediatrics and CDC recommend starting treatment within the first 3 days of symptom onset for maximum efficacy 3
- Clinical improvement should be monitored within 48-72 hours 3, 4
Monitoring and Safety
- The CDC and National Institutes of Health recommend ensuring adequate hydration throughout treatment to prevent acyclovir crystalluria 3, 4
- Renal function should be monitored, particularly with prolonged use 1
- Neutropenia should be watched for with extended therapy (21-46% in prolonged courses, though typically self-limited) 3
Treatment Failure or Resistance
- For acyclovir-resistant HSV, the CDC recommends considering foscarnet 40 mg/kg IV three times daily 1, 2, 3
Special Populations
- For neonates with genital HSV, higher doses of acyclovir are required, with a recommended dose of 20 mg/kg IV every 8 hours 3