Drug Characteristics
  • Formulation

    Tablets: 125mg, 250 mg, 500 mg, 750 mg

  • Dose

    Not usually recommended as first line due to cost (see aciclovir)

    Herpes simplex: 500 mg twice a day for 7 days.

    Herpes zoster: 500 mg orally three times a day for 10 days.

    Herpes simplex prophylaxis: 500 mg twice a day continuously.        

  • Side Effects

    Headache; nausea; rash; dizziness; confusion; abdominal pain and fever have been reported in immunocompromised patients

  • Interactions

    No significant drug interactions

  • Renal

    Herpes zoster:

    GFR >40: 500 mg three times a day

    GFR 30–39: 250 mg three times a day.

    GFR 10–29: 125 mg three times a day.

    Herpes simplex:

    GFR >40: 500 mg two times a day.

    GFR 30–39: 250 mg two times a day

    GFR10–29: 125 mg two times a day

    A dose interval of 48 hours is recommended for haemodialysis patients for periods between dialysis. Famciclovir must be administered immediately after dialysis, as 4 hours of haemodialysis reduce the plasma concentration by approximately 75%.        

  • Hepatic

    Dosage modification is not required for patients with well-compensated chronic liver disease

    There is no information on patients with decompensated liver disease        

  • Pregnancy

    Limited Human Data – Animal Data Suggest Low Risk

  • Other Information