C. diff Risk


Oral Bioavailability


Approximate Cost

IV: $$$$
PO: $

Spectrum Of Activity


5-10mg/kg IV q8h. Consider higher dosing for serious infections such as CNS and disseminated zoster

800mg PO 5 times per day for shingles

Prophylaxis dosing varies by indication

Use ideal body weight for dosing

CrCl > 50 mL/minCrCl 10 - 50 mL/minCrCl < 10mL/min (ESRD not on HD)Dialysis (HD)Dialysis (CRRT)5 mg/kg/dose IV Q8h5 mg/kg/dose IV Q12 -24h2.5 mg/kg IV Q24h2.5mg/kg IV x1 now then 2.5 mg/kg QPM (give PHD on HD days)5mg/kg Q24h

CrCl > 50 mL/minCrCl 10 - 50 mL/minCrCl < 10mL/min (ESRD not on HD)Dialysis (HD)Dialysis (CRRT)10 mg/kg/dose IV Q8h10 mg/kg/dose IV Q12 - 24h5 mg/kg IV Q24h5mg/kg IV x1 now then 5 mg/kg QPM (give PHD on HD days)5-10mg/kg Q12h -24h

Creatinine Clearance >50mL/min/1.73m² Creatinine Clearance 25-50mL/min/1.73m² Creatinine Clearance 10-24mL/min/1.73m² Creatinine Clearance ≤ 10mL/min/1.73m² HSV neonate <3mo: 20mg/kg/dose IV Q8H20mg/kg/dose IV Q12H20mg/kg/dose IV Q24H10mg/kg/dose IV Q24H

Dosing of acyclovir varies by immune status and indication. Please consult pediatric infectious diseases and/or pharmacy for dosing recommendations.

General Information

  • Malaise

  • Nausea

  • Vomiting

  • Diarrhea

  • Phlebitis (with IV acyclovir)

  • Nephrotoxicity

  • CNS effects with high-dose IV therapy


  • Cr twice weekly with IV acyclovir (dose adjustment and nephrotoxicity assessment)


  • Phlebitis

  • CNS effects (IV)

  • GI effects

  • Ensure adequate hydration for IV acyclovir

Mycophenolate can increase the acyclovir concentration

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

Pregnancy category: B

Average serum half life: 3 hours

CSF penetration: Therapeutic

Urine penetration: Therapeutic

Therapy for herpesviral infections (HSV and VZV) including encephalitis

Prophylaxis of herpesviral infections if recurrent disease or immunocompromised