Famvir
The comparative effects of famciclovir and valacyclovir on herpes simplex virus type 1 infection, latency, and reactivation in mice.

LeBlanc RA, Pesnicak L, Godleski M, Straus SE.

Medical Virology Section, Laboratory of Clinical Investigation, National Institutes of Health, Bethesda, Maryland 20892-1888, USA.

Infections by herpes simplex virus (HSV) cannot yet be eliminated, but the severity of the disease can be reduced. Two newer drugs with established efficacy for such infections, famciclovir and valacyclovir, were tested in a mouse eye model of HSV infection. Both drugs significantly reduced mortality and titers of virus shed from the eyes of mice infected with an otherwise lethal dose of HSV type 1 (HSV-1). Similar titers of HSV-1 were found in the eyes, ganglia, and brains of treated animals. Although valacyclovir reduced the latent viral DNA load better in these studies than did famciclovir, rates of reactivation by explantation and UV exposure were the same. Thus, in this study, famciclovir and valacyclovir were equally effective in limiting the virulence and spread of HSV-1, despite their biochemical and pharmacologic differences.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10438344&dopt=Abstract famciclovir Famvir



Famvir
Recent clinical experience with famciclovir--a "third generation" nucleoside prodrug.

Chakrabarty A, Tyring SK, Beutner K, Rauser M.

Solano Research, Davis, Calif, USA. chakak3 yahoo.com

The herpesviruses continue to produce considerable morbidity in man. Once infected with herpes simplex (HSV), the virus remains dormant within the nervous system and may reactivate if provoked by stress, trauma and/or other factors. To date, there is no cure, but antiviral medication can reduce duration and severity of symptoms and prophylaxis can suppress recurrent episodes of disease. The second-generation guanosine nucleosides, acyclovir and penciclovir, are effective inhibitors with low toxicity; both, however, have relatively low oral bioavailability. Subsequently, the orally bioavailable prodrugs valaciclovir and famciclovir have been introduced. These compounds offer high oral bioavailabilty and deliver acyclovir and penciclovir, respectively, to the target cells by means of more convenient dosing schedules. This short review points to recent experience with famciclovir in the management of HSV and varicella-zoster virus.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15535046&dopt=Abstract famciclovir Famvir



Famvir
Treatment of postherpetic neuralgia.

Sra KK, Tyring SK.

University of Texas, Health Sciences Center, Houston, Texas, USA.

Postherpetic neuralgia (PHN) is a serious complication of herpes zoster that has a predilection for older individuals. PHN is often associated with significant morbidity, and it can cause insomnia, fatigue, depression and interference with daily activities in affected individuals. Treatment for PHN is initiated with antivirals during the acute herpes zoster outbreak. Acyclovir (Zoviraxr, GlaxoSmithKline), valacyclovir (Valtrex, GlaxoSmithKline) or famciclovir (Famvir, Novartis) can be used to treat herpes zoster, and all three have been shown to reduce the duration of the herpetic rash and zoster-associated pain. These antivirals are most effective when used within the first 72 hours of the onset of the rash. Side-effects of these antivirals are low and include nausea, vomiting, abdominal pain and headache. Other treatment options for PHN include topical analgesics, opioid analgesics, tricyclic antidepressants and gabapentin. Because of the complexity of PHN, most patients require a combination of treatment modalities for adequate pain relief.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15550990&dopt=Abstract famciclovir Famvir



Famvir
Randomized double-blinded, placebo-controlled clinical trial of famciclovir for reduction of Meniere's disease symptoms.

Derebery MJ, Fisher LM, Iqbal Z.

House Ear Institute, Los Angeles, California 90057, USA. jderebery hei.org

OBJECTIVE: To conduct a clinical trial of famciclovir for symptom control in Meniere's disease. STUDY DESIGN AND SETTING: Randomized, double-blinded placebo-controlled clinical trial in a tertiary referral center, with 12 subjects in the active treatment arm and 11 subjects in the placebo arm. RESULTS: There were no serious adverse events. Twenty-five percent of the famciclovir group and 18% of the placebo group showed a reduction in number of vertigo spells, the primary efficacy endpoint. This difference was not statistically significant. All subjects improved in dizziness and health-related quality of life. There was a trend for the famciclovir arm to have less fluctuation in hearing relative to the placebo arm. CONCLUSION: No dramatic effects of famciclovir were found on vertigo or dizziness. Some promising effects on reduction of the fluctuation in hearing were observed. SIGNIFICANCE: Famciclovir may suppress the fluctuation of hearing in Meniere's disease, but had a minimal effect on vertigo or dizziness symptoms in this study. The probable multifactorial etiology in Meniere's disease requires that further studies be conducted to determine the effects of antiviral medications. EBM RATING: A.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15577784&dopt=Abstract famciclovir Famvir



Famvir
Effect of formulary policy decisions on antimicrobial drug utilization in British Columbia.

Marra F, Patrick DM, White R, Ng H, Bowie WR, Hutchinson JM.

Faculty of Pharmaceutical Sciences, Health Care and Epidemiology, Division of Infectious Diseases, Department of Medicine, Vancouver Hospital and Health Sciences Centre, University of British Columbia, Vancouver, Canada. fawziah.marra bccdc.ca

Background: Formularies are used routinely for management of drug expenditures yet evaluations of their impact remain rare. The objective of this study was to analyse the impact of addition or deletion of antimicrobials from the provincial formulary on drug utilization. METHODS: We obtained data from the British Columbia PharmaNet database on all outpatient oral antimicrobial prescriptions from 1996 to 2000 and converted them to their defined daily dose (DDD) equivalents according to the ATC system. Trends in utilization associated with a changing formulary status of new antimicrobial agents were analysed. Maximum likelihood estimation was used to determine the rate of increase in utilization resulting from addition to the formulary. Models were adjusted for seasonal and temporal trends as well as serial correlation. RESULTS: During this time period, clarithromycin was on formulary, later delisted, and then relisted again. Valaciclovir and famciclovir were also added to the formulary. During the time clarithromycin was off the formulary, the rate of change in its monthly consumption was 0.0061 DDD/1000 population/day; following its relisting, the rate of change increased by 818% to 0.0560 DDD/1000 population/day (P=0.002). After the listing of valaciclovir on the formulary, the rate of change in its monthly consumption increased 57% from a baseline of 0.0014 to 0.0022 DDD/1000 population/day (P=0.07). A similar effect was seen with the addition of famciclovir to the formulary whereby the rate of change in monthly consumption increased from 0.0008 (before addition to the formulary) to 0.0018 (after addition to the formulary) (P </= 0.001). CONCLUSIONS: Listing of antimicrobials on provincial or countrywide formularies is followed temporally with increased utilization. However, before governmental agencies can institute reference-based pricing or co-payment programmes, the effect of such a programme on the emergence of antimicrobial resistance and on patient outcomes needs further study.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15590717&dopt=Abstract famciclovir Famvir