Acyclovir (Zovirax)


  • Antiviral


  • Purine nucleotide that inhibits viral replication


  • Genital herpes treatment and prophylaxis

  • Mucosal and cutaneous herpes simplex (HSV-1 and HSV-2) treatment and prophylaxis

  • Varicella-zoster (chickenpox & shingles)  


  • Pregnancy category C

  • Dosing modification is required for patients with impaired renal function.

  • Avoid sexual contact when genital lesions are present.

  • Medication treatment is not a cure for viral infection.

  • Do not exceed recommended dose.

  • Initiate therapy at earliest signs of symptoms.

  • Use rubber gloves or a finger cot when applying topical cream to active lesions, so as not to inoculate other areas.

  Adverse Reactions (Side Effects):

  • Malaise (11.5%)

  • Nausea and vomiting (2-8%)

  • Headache (6%)

  • Pain / phlebitis at injection site (9%)


Administered as an oral tablet, capsule, topical cream or injection

Parenteral (avoid rapid IV, IM or SQ injections, administer via slow IV infusion):

Mucosal and cutaneous HSV infections:

  • 5mg/kg infused over 1 hour, every 8 hours for 7 days

Varicella-zoster (shingles) infections:

  • 10mg/kg infused over 1 hour, every 8 hours for 7 days

Herpes simplex encephalitis:

  • 10mg/kg infused over 1 hour, every 8 hours for 10 days


Herpes simplex:

  • Initial infection: 200mg q4h (5 times a day) for 10 days

  • Chronic suppression: 400mg bid for 12 months

  • Intermittent therapy: 200mg q4h (5 times a day) for 5 days

Herpes zoster, acute treatment

  • 800mg q4h (5 times a day) for 7-10 days


  • 20mg/kg (not to exceed 800mg) qid for 5 days


  • Apply a sufficient quantity to adequately cover all lesions q3h (6 times a day) for 7 days.

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