Famvir - General Information
Famvir is a guanine analogue antiviral drug used for the treatment of various herpesvirus infections, most commonly for herpes zoster (shingles). It is a prodrug form of penciclovir with improved oral bioavailability. Famvir is marketed under the trade name Famvir (Novartis).
Pharmacology of Famvir
Famvir 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.
Famvir for patients
Patients should be informed that Famvir is not a cure for genital herpes. There are no data evaluating whether Famvir will prevent transmission of infection to others. As genital herpes is a sexually transmitted disease, patients should avoid contact with lesions or intercourse when lesions and/or symptoms are present to avoid infecting partners. Genital herpes can also be transmitted in the absence of symptoms through asymptomatic viral shedding. If medical management of recurrent episodes is indicated, patients should be advised to initiate therapy at the first sign or symptom.
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.
Famvir (famciclovir) is contraindicated in patients with known hypersensitivity to the product, its components, and Denavir (penciclovir cream).
Additional information about Famvir
Famvir Indication: 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.
Mechanism Of Action: Famvir 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.
Drug Interactions: Not Available
Food Interactions: Take without regard to meals.
Generic Name: Famciclovir
Synonyms: Not Available
Drug Category: Prodrugs; Nucleosides and Nucleotides; Antiviral Agents
Drug Type: Small Molecule; Approved
Absorption: 77 %
Toxicity (Overdose): Symptoms of overdose include constipation, diarrhea, dizziness, fatigue, fever, headache, nausea, and vomiting.
Protein Binding: 20-25%
Half Life: 10 hours
Dosage Forms of Famvir: Tablet Oral
Chemical IUPAC Name: [2-(acetyloxymethyl)-4-(2-aminopurin-9-yl)butyl] acetate
Chemical Formula: C14H19N5O4
Famciclovir on Wikipedia: https://en.wikipedia.org/wiki/Famciclovir
Organisms Affected: Human Herpes Virus