Famvir

Herpes zoster (shingles), Recurrent herpes labialis, Genital herpes, Acute treatment of recurrent mucocutaneous herpes in HIV-infected patients, Acute treatment of recurrent episodes of genital herpes, Suppression of recurrent episodes of genital herpes

Herpes simplex & Varicella-zoster virus infections

Famciclovir rapidly undergoes biotransformation to penciclovir, which has inhibitory activity against HSV types 1 (HSV-1) and 2 (HSV-2), varicella-zoster virus (VZV). Thymidine kinase then phosphorylates penciclovir to a monophosphate form, which is then converted to penciclovir triphosphate. This inhibits HSV-2 DNA polymerase by competing with deoxyguanosine triphosphate, thus inhibiting herpes viral DNA synthesis and replication.

Oral (Adult)-

Herpes zoster (shingles): 500 mg tid for 7 days. Immunocompromised patients: 500 mg tid for 10 days.

Haemodialysis patients: 250 mg after each dialysis run during 7 days. Immunocompromised patients: Same dose but treatment is given for 10 days.

• CrCl (mL/min) <20: 250 mg once daily for 7 days.
• CrCl (mL/min) 20-39: 500 mg once daily for 7 days.
• CrCl (mL/min) 40-59: 500 mg bid for 7 days.

Recurrent herpes labialis: 1.5 g as a single dose.

Haemodialysis patients: 250 mg after dialysis run.

• CrCl (mL/min) <20: 250 mg as a single dose.
• CrCl (mL/min) 20-39: 500 mg as a single dose.
• CrCl (mL/min) 40-59: 750 mg as a single dose.

Genital herpes: 1st episode: 250 mg tid for 5 days. Immunocompromised patients: 500 mg bid for 7 days.

Haemodialysis patients: 250 mg after each dialysis run during 5 days.

• CrCl (mL/min) <20: 250 mg once daily for 5 days.
• CrCl (mL/min) 20-39: 250 mg bid for 5 days.

Acute treatment of recurrent mucocutaneous herpes in HIV-infected patients: 500 mg bid for 7 days.

Haemodialysis patients: 250 mg after each dialysis run during 7 days.

• CrCl (mL/min) <20: 250 mg once daily for 7 days.
• CrCl (mL/min) 20-39: 500 mg once daily for 7 days.

Acute treatment of recurrent episodes of genital herpes: 125 mg bid for 5 days or 1 g bid for 1 day. Immunocompromised patients: 500 mg bid for 7 days.

Haemodialysis patients: 125 mg after each dialysis run during 5 days. Haemodialysis patients (immunocompromised): 250 mg after each dialysis run during 7 days.

• CrCl (mL/min) <20: 125 mg once daily for 5 days.
• CrCl (mL/min) ≥20: 125 mg bid for 5 days.
• CrCl (mL/min) <20: Immunocompromised: 250 mg once daily for 7 days.
• CrCl (mL/min) 20-39: Immunocompromised: 500 mg once daily for 7 days.

Suppression of recurrent episodes of genital herpes: 250 mg bid. Immunocompromised patients: 500 mg bid. Suppressive treatment is interrupted every 6-12 mth for observation.

Haemodialysis patients: 125 mg after each dialysis run. Haemodialysis patients (immunocompromised): 250 mg after each dialysis run.

• CrCl (mL/min) 20: 125 mg once daily. Immunocompromised: 250 mg once daily.
• CrCl (mL/min) 20-39: 125 mg bid. Immunocompromised: 500 mg once daily.

Headache, nausea, diarrhoea, fatigue, dizziness, fever, paraesthesia, somnolence, vomiting, constipation, anorexia, abdominal pain, flatulence, dyspepsia; increased serum levels of ALT, alkaline phosphatase, total bilirubin and albumin; pruritus, pharyngitis, sinusitis, injury, generalised pain, rigors, back pain, arthralgia; increased serum phosphate, Na and K levels; abnormal leukocyte counts, purpura, angioedema.

Hypersensitivity to famciclovir and penciclovir.

Renal impairment. Pregnancy and lactation.

Reduced renal excretion resulting to increased plasma concentration w/ probenecid. Raloxifen may reduce the formation of penciclovir, the active metabolite of famciclovir.

Category B: Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).

Acute renal failure in patients with renal disease. Management: Supportive and symptomatic treatment. May be removed by haemodialysis.

Store at 20-25°C.