Brands, Medical Use, Clinical Data
Drug Category
- Prodrugs
- Antivirals
- Nucleosides and Nucleotides
Dosage Forms
Brands / Synonyms
Famciclovir 98.5; Famciclovir [Usan:Ban:Inn]; Famciclovirum [Inn-Latin]; Famvir; Famvir
; FCV
Indications
For the treatment of acute herpes zoster (shingles). Also for the treatment or suppression of recurrent genital herpes in immunocompetent patients and treatment of recurrent mucocutaneous herpes simplex infections in HIV infected patients.
Pharmacology
Famciclovir is a prodrug that undergoes rapid biotransformation to the active antiviral compound penciclovir. Penciclovir is an anti-viral drug which has inhibitory activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) and varicella zoster virus (VZV). Therefore, herpes viral DNA synthesis and replication are selectively inhibited.
Mechanism of Action
Famciclovir undergoes rapid biotransformation to the active antiviral compound penciclovir, which has inhibitory activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) and varicella zoster virus (VZV). In cells infected with HSV-1, HSV-2 or VZV, viral thymidine kinase phosphorylates penciclovir to a monophosphate form that, in turn, is converted to penciclovir triphosphate by cellular kinases. In vitro studies demonstrate that penciclovir triphosphate inhibits HSV-2 DNA polymerase competitively with deoxyguanosine triphosphate. Consequently, herpes viral DNA synthesis and, therefore, replication are selectively inhibited.
Absorption
77 %
Toxicity
Symptoms of overdose include constipation, diarrhea, dizziness, fatigue, fever, headache, nausea, and vomiting.
Biotrnasformation / Drug Metabolism
Hepatic
Contraindications
Famvir (famciclovir) is contraindicated in patients with known hypersensitivity to the product, its components,
and Denavir® (penciclovir cream).
Drug Interactions
Concurrent use with probenecid or other drugs significantly eliminated by active renal tubular secretion may
result in increased plasma concentrations of penciclovir.
The conversion of 6-deoxy penciclovir to penciclovir is catalyzed by aldehyde oxidase. Interactions with other
drugs metabolized by this enzyme could potentially occur.
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