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

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.

Single-day, patient-initiated famciclovir therapy versus 3-day valacyclovir regimen for recurrent genital herpes: a randomized, double-blind, comparative trial.

BACKGROUND: Recurrent genital herpes is a major problem for patients worldwide. Early episodic treatment with short-course therapy is effective, often stopping progression of outbreaks. This study is the first head-to-head comparison of single-day famciclovir (1000 mg administered twice daily) versus 3-day valacyclovir (500 mg administered twice daily) for episodic therapy in immunocompetent patients. METHODS: In this multicenter, multinational, double-blind, parallel-group study, 1179 adults with a history of recurrent genital herpes were randomized 1:1 to receive either famciclovir or valacyclovir. Patients initiated treatment within 6 h after a recurrence. The primary objective was to establish noninferiority of single-day famciclovir, compared with a 3-day course of valacyclovir, in time to healing of all nonaborted lesions in a modified intent-to-treat population. RESULTS: This study established that single-day famciclovir therapy was noninferior to 3-day valacyclovir therapy in reducing time to healing of all nonaborted genital herpes lesions (median time to healing, 4.25 days vs. 4.08 days). Approximately one-third of patients in each treatment group had aborted genital herpes episodes, suggesting that both treatments have similar efficacy in preventing outbreaks or progression of lesions beyond the papule stage. There was no significant difference in time to resolution of symptoms associated with recurrence. The overall incidence of adverse events was similar (23.2% for the famciclovir group vs. 22.3% for the valacyclovir group), with headache, nausea, diarrhea, vomiting, and abdominal pain reported most often. CONCLUSIONS: Single-day famciclovir (1000 mg administered twice daily) was similar to 3-day valacyclovir (500 mg administered twice daily) in both efficacy and safety, representing a more convenient treatment for immunocompetent adults with recurrent genital herpes.