C difficile risk
Oral Bioavailability

Spectrum Of Activity


0 - 3 months 60mg/kg/DAY divided q8h

3 months - 12 years 12 years+ 30-45mg/kg/DAY divided q8h30mg/kg/DAY divided q8h

15mg/kg/DAY divided q8h

30mg/kg/DAY divided q8h

HSV prophylaxis:

300mg/m2/DOSE q8hHSV mucocutaneous inf:

40-80mg/kg/DAY divided q6-8hVaricella:

80mg/kg/DAY divided q6h

PNA-days 0 - 14PNA-days 15 - 28IV: 20 mg/kg/dose every 12 hoursIV: 20 mg/kg/dose every 8 hours

PNA-days 0 - 7PNA-days 8 - 28IV: 20 mg/kg/dose every 12 hoursIV: 20 mg/kg/dose every 8 hours

IV: 20 mg/kg/dose every 8 hours

Renally cleared, requires dosage adjustment with changes in renal function. Consult a pharmacist for renal dosing.

Given a current drug shortage, intravenous prescriptions for acyclovir beyond 24 hours will need approval by Infectious Disease

General Information

  • Therapy for herpesviral infections (HSV and VZV) including encephalitis

  • Prophylaxis of herpesviral infections if recurrent disease or immunocompromised

Follow SCr, BUN, urine output as appropriate, liver enzymes and CBC.

  • Nausea

  • Vomiting

  • Diarrhea

  • Headache

  • Phlebitis (IV)

  • Liver or renal dysfunction

  • Crystal nephropathy (keep patient well hydrated)

  • May diminish efficacy of zoster or varicella vaccine.

  • For oral indications, Valacyclovir is the pro-drug and is more bioavailable with more convenient dosing.

Antimicrobial class: Antiviral, nucleoside analogue

Average serum half life: Neonates: 4 hours
Children 1-12 years: 2-3 hours

Route of Elimination: Primarily kidney with 60-90% of drug excreted unchanged in the urine