Acyclovir

General

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

Adult Dosing

• HSV Encephalitis
  • 10 mg/kg IV q8h x 10 d

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

• Varicella
  • Immunocompetent
    • 800 mg PO QID x 5-7 d
  • Immunocompromised
    • 10 mg/kg IV q8h x 7 d
• Herpes Zoster
  • Immunocompetent
    • 800 mg PO 5x/day x 7 d
  • Immunocompromised
    • 10 mg/kg IV q8h x 7 d

• Zoster Ophthalmicus
  • 800 mg PO 5x/day x 7 d

• HSV prophylaxis in immunocompromised
  • 400-800 mg PO BID-TID

• HSV keratitis
  • 400 mg PO 5x/day

Special Populations

• Pregnancy Rating: B
• Lactation: Safe
• Renal Dosing
  • Adult
    • IV
      • CrCl 25-50 give q12h
      • CrCl 10-24 give q24h
      • CrCl <10 decr. 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
• Caution in renal impairment
• Caution in concurrent nephrotoxic agent use
• Caution in dehydration
• Caution in electrolyte abnl
• Caution in hypoxia
• Caution in neurologic dz
• Caution in hepatic impairment
• Caution in elderly

Adverse Reactions

Serious

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

Pharmacology

• Half-life: 2.5 - 3.3 hrs
• Metabolism: other
• Excretion: Urine
• Mechanism of Action: Inhibits DNA polymerase