Acyclovir

General

  • Type: Antiviral: guanosine analog
  • Dosage Forms: IV, PO
  • Common Trade Names: Zovirax

Adult Dosing

  • Genital/Mucocutaneous HSV
    • Immunocompetent
      • 1st episode, Mild-mod: 400mg PO TID x 7-10 d
      • 1st episode, Severe: 5-10mg/kg IV q8h x 2-7 d
      • Recurrence: 400mg PO TID x 5 d
      • Suppression: 400mg PO BID
    • Immunocompromised
      • 1st episode: 400mg PO TID x 5-10 d
      • Recurrence: 400mg PO TID x 5-10 d
      • Suppression: 400-800mg PO BID-TID
  • Varicella
    • Immunocompetent
      • 800mg PO QID x 5-7 d
    • Immunocompromised
      • 10mg/kg IV q8h x 7 d
  • Herpes Zoster
    • Immunocompetent
      • 800mg PO 5x/day x 7 d
    • Immunocompromised
      • 10mg/kg IV q8h x 7 d
  • Herpes Zoster
    • Immunocompetent
      • 800mg PO 5x/day x 7 d
    • Immunocompromised
      • 10mg/kg IV q8h x 7 d
  • HSV prophylaxis in immunocompromised
    • 400-800mg PO BID-TID

Pediatric Dosing

  • Neonatal HSV
    • 40-60mg/kg/day IV divided q12h x 14-21 d
  • HSV encephalitis
    • 3 mo - 11 y/o
      • 30-45mg/kg/day IV divided q8h x 14-21 d
    • >12 y/o
      • 30mg/kg/day IV divided q8h x 14-21 d
  • Genital/mucocutaneous HSV
    • Immunocompetent
      • 1st episode, 2-11 y/o
        • 40-80mg/kg/day PO divided q6-8 h x 5 d, max 1g/day
      • 1st episode, >12 y/o
        • 1g/day PO divided 5x/day x 7-10 d
    • Immunocompromised
      • PO: >2 y/o: 1g/day PO divided 3-5x/day x 7-14 d
      • IV: >1 y/o: 30mg/kg/day IV divided q8h x 7-14 d
  • Varicella
    • Immunocompetent
      • PO: > 2 y/o: 80mg/kg/day PO divided q6h x 5 d
      • IV: > 1 y/o: 30mg/kg/day IV divided q8h x 7-10 d
    • Immunocompromised
      • 30mg/kg/day IV divided q8h x 7-10 d
  • Herpes zoster
    • Immunocompetent
      • PO: > 12 y/o: 4g/day PO divided 5x/day x 5-7 d
      • IV: 30mg/kg/day IV divided q8h x 7-10 d
    • Immunocompromised
      • 30mg/kg/day IV divided q8h x 7-10 d


Special Populations

  • Pregnancy Rating: B
  • Lactation Risk Categories: Safe
  • Renal Dosing
    • Adult
      • IV
        • CrCl 25-50 give q12h
        • CrCl 10-24 give q24h
        • CrCl <10 decrease dose 50%, give q24h
        • HD give usual dose as supplement
        • PD no supplement
      • PO
        • CrCl <25: see package insert
        • HD: give usual dose as supplement
        • PD: no supplement
    • Pediatric
  • Hepatic Dosing
    • Not defined

Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

  • Hallucinations / psychosis
  • Seizure
  • Coma
  • Encephalopathy
  • Thrombocytopenia
  • Leukopenia
  • Anaphylaxis
  • Angioedema
  • Erythema Multiforme
  • SJS / TEN / TTP
  • Hepatitis
  • Renal failure

Common

  • Nausea/vomiting/diarrhea
  • Headache
  • Dizziness
  • Rash
  • Arthralgia
  • Confusion / lethargy
  • Elev. BUN/creatinine
  • Photosensitivity

Pharmacology

  • Half-life: 2.5 - 3.3 hrs
  • Metabolism: virally infected cells (intracellularly); liver
  • Excretion: Urine
  • Mechanism of Action: Inhibits DNA polymerase

See Also

References

  • Epocrates 2015