Famciclovir

DEA Class; Rx

Common Brand Names; Famvir

• Antivirals, Other

Oral antiviral agent; prodrug for penciclovir
Indicated for tx of acute herpes zoster, tx or suppression of recurrent genital herpes in immunocompetent patients, acute tx of recurrent herpes labialis in immunocompetent patients, and tx of recurrent mucocutaneous herpes simplex infection in HIV patients
Similar spectrum of activity to acyclovir but longer duration of action

Known hypersensitivity to this drug or its active metabolite, penciclovir

• Headache (23%)
• Nausea (13%)
• Diarrhea (2-9%)
• Abdominal pain (8%)
• Dysmenorrhea (<8%)
• Vomiting (1-5%)
• Flatulence (5%)
• Pruritus (4%)
• Rash (3%)
• Paresthesia (3%)
• Neutropenia (3%)
• Increased transaminases (2-3%)
• Increased bilirubin (2%)
• Fatigue (1%)

Dosage must be adjusted in renal impairment; there is a risk of acute renal failure (ARF) with inappropriately high dosage

Patients with galactose intolerance, glucose-galactose malabsorption syndrome, or severe lactase deficiency should discuss it with practitioner (famciclovir tablets contain lactose)

Available data from pharmacovigilance reports in pregnant women have not identified a drug- associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes

There are no data on presence of famciclovir (prodrug) or penciclovir (active drug) in human milk

2,000 mg/day PO for single-day therapy or 1,500 mg/day PO for multiple-day therapy.

2,000 mg/day PO for single-day therapy or 1,500 mg/day PO for multiple-day therapy.

Safety and efficacy have not been established; however, doses up to 2,000 mg/day PO for single-day therapy or 1,500 mg/day PO for multiple-day therapy have been used off-label.

weight 45 kg or more: Safety and efficacy have not been established; however, doses up to 2,000 mg/day PO for single-day therapy or 1,000 mg/day PO for multiple-day therapy have been used off-label.
weight less than 45 kg: Safety and efficacy have not been established.

Safety and efficacy have not been established.

Safety and efficacy have not been established