Single-day famciclovir for the treatment of genital herpes: follow-up results of time to next recurrence and assessment of antiviral resistance^*

ABSTRACT

Background: Episodic therapy of genital herpes is usually recommended for patients with infrequent symptomatic recurrences and where transmission is not a concern. While shorter courses are as effective as standard 5-day regimens, it is unknown whether abbreviated therapy has detrimental effects on natural history and the development of antiviral resistance.

Objectives: To assess time to next recurrence and development of antiviral resistance in patients with recurrent genital herpes treated with either single-day famciclovir (1 g twice-daily) or 3-day valacyclovir (500 mg twice-daily).

Methods: Longer-term, follow-up data on the time to next recurrence and antiviral sensitivity were collected from a previously reported multicenter, multinational, double-blind, parallel group study in which 1179 immunocompetent adults were randomized 1 : 1 to receive either single-day famciclovir or 3-day valacyclovir. Treatment was self-initiated within 6 hours of a recurrence. Swabs for viral culture and sensitivity testing were collected for two sequential recurrences.

Results: The median time to next recurrence from treatment initiation was 33.5 days for famciclovir and 38.0 days for valacyclovir. No drug resistance to penciclovir, the active metabolite of famciclovir, was observed at baseline nor did any develop by the time of the next recurrence.

Limitations: The study had no placebo arm, typing of viral isolates was not performed and viral resistance testing was restricted to penciclovir only.

Conclusion: Treatment with single-day famciclovir for recurrent genital herpes did not shorten the time to the next recurrence. Drug resistance to penciclovir continues to be a rare event in immunocompetent patients.

Key words: :

• Drug resistance
• Famciclovir
• Genital herpes
• Single-day therapy
• Time to next recurrence

Acknowledgments

Declaration of interest: Funding for the study and for editorial assistance was provided by Novartis. N. B. has been a consultant for and has received research funding from Novartis and GlaxoSmithKline. K. F. has received research funding from Novartis, GlaxoSmithKline, Astellas, Antigenics, and Gilead. W. K. has received research funding and speakers’ honoraria from Novartis, Bayer, Biosante, Boehringer Ingelheim, Duramed, Dynogen, GlaxoSmithKline, Kanion, Merck, Neurocrine Biosciences, Nventa, Pharm-Olam International, Proctor and Gamble, Roche, Sanofi Aventis, Shionog, Tap Pharmaceuticals, Upsher Smith, Warner Chilcott, Wyeth, Xanodyne Pharmaceuticals, and 3M. S. T. has received research funding and speakers’ honoraria from Novartis and GlaxoSmithKline. M. A. has received research funding and speakers’ honoraria from Novartis. M. P. has received research funding from Novartis, specifically for HSV phenotypic resistance testing. K. H. is an employee of Novartis. Editorial assistance for this manuscript was provided by freelancer Teresa Tartaglione. The study was registered with www.ClinicalTrials.gov; trial identifier NCT00306787.

Notes

* Portions of the data in this paper were presented at the 48th Interscience Conference on Antimicrobial Agents and Chemotherapy/46th Annual Meeting of the Infectious Diseases Society of America, October 25–28, 2008, Washington, DC, USA (Abstract #564)