Famciclovir is a guanosine 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. Famciclovir is marketed under the trade name Famvir (Novartis).
Famciclovir was patented in 1983 and approved for medical use in 1994.[2][3] In 2007, the United States Food and Drug Administration approved the first generic version of famciclovir. Generic tablets are manufactured by TEVA Pharmaceuticals and Mylan Pharmaceuticals.[4][5]
Medical uses
Famciclovir is indicated for the treatment of herpes zoster (shingles),[6] treatment of herpes simplex virus 2 (genital herpes),[7] herpes labialis (cold sores) in immunocompetent patients[8] and for the suppression of recurring episodes of herpes simplex virus 2. It is also indicated for treatment of recurrent episodes of herpes simplex in HIV patients.
Adverse effects
Side effects: mild to extreme stomach upset, headaches, mild fever.
Herpes
Early treatment
Several studies in humans and mice provide evidence that early treatment with famciclovir soon after the first infection with herpes can significantly lower the chance of future outbreaks. Use of famciclovir in this manner has been shown to reduce the amount of latent virus in the neural ganglia compared to no treatment or treatment with valaciclovir.[9][10][11] A review of human subjects treated for five days with famciclovir 250 mg three times daily during their first herpes episode found that only 4.2 percent experienced a recurrence within six months after the first outbreak, a fivefold decrease compared to the 19 percent recurrence in acyclovir-treated patients.[12] Neither drug affected latency if treatment was delayed for several months.[13]
History
Initially studied as compound BRL 42810, famciclovir grew out of the study of "several potential prodrugs of penciclovir", that were synthesized by M. R. Harnden and R. L. Jarvest from the Beecham Group plc. in the late 1980s. After showing promise on studies with mice, BRL 42810 (famciclovir) was selected for further evaluation and progression to studies in humans. [14]
References
- Prescription medicines: registration of new generic medicines and biosimilar medicines, 2017 Therapeutic Goods Administration (TGA), 21 June 2022, retrieved 30 March 2024^
- Principles and Practice of Pediatric Infectious Disease Elsevier Health Sciences, 2012^
- Analogue-based Drug Discovery John Wiley & Sons, 2006^
- Recent Product Launches, Teva Pharmaceuticals USA retrieved 2008-02-21^
- Mylan Launches Generic Version of Famvir® Tablets Mylan, 20 April 2011, retrieved 21 April 2011^
- Famciclovir for the treatment of acute herpes zoster: effects on acute disease and postherpetic neuralgia. A randomized, double-blind, placebo-controlled trial. Collaborative Famciclovir Herpes Zoster Study Group Annals of Internal Medicine, July 1995^
- Famciclovir for treatment of herpesvirus infections The Annals of Pharmacotherapy, September 1996^
- Single-dose, patient-initiated famciclovir: a randomized, double-blind, placebo-controlled trial for episodic treatment of herpes labialis Journal of the American Academy of Dermatology, July 2006^
- The effects of antiviral therapy on the distribution of herpes simplex virus type 1 to ganglionic neurons and its consequences during, immediately following and several months after treatment The Journal of General Virology, October 2000^
- Famciclovir and valaciclovir differ in the prevention of herpes simplex virus type 1 latency in mice: a quantitative study Antimicrobial Agents and Chemotherapy, July 1998^
- Persistence of infectious herpes simplex virus type 2 in the nervous system in mice after antiviral chemotherapy Antimicrobial Agents and Chemotherapy, January 2000^
- Observation May Indicate A Possible Clinical Effect On Latency Doctor's Guide Publishing Limited^
- Differential effects of famciclovir and valaciclovir on the pathogenesis of herpes simplex virus in a murine infection model including reactivation from latency The Journal of Infectious Diseases, February 1996^
- Selection of an oral prodrug (BRL 42810; famciclovir) for the antiherpesvirus agent BRL 39123 [9-(4-hydroxy-3-hydroxymethylbut-l-yl)guanine; penciclovir] Antimicrobial Agents and Chemotherapy, October 1989^