Tablets: 125mg, 250 mg, 500 mg, 750 mg
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.
Headache; nausea; rash; dizziness; confusion; abdominal pain and fever have been reported in immunocompromised patients
No significant drug interactions
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.
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%.
Dosage modification is not required for patients with well-compensated chronic liver disease
There is no information on patients with decompensated liver disease
Limited Human Data – Animal Data Suggest Low Risk