Early, High-Dose Famciclovir May Prevent Recurrent Genital Herpes

Manufacturer Is Applying for New, Single-Day Indication

WASHINGTON, DC?It now appears that 1000 mg of oral famciclovir (Famvir; Novartis) on the first day of an outbreak of recurrent genital herpes lesions is superior to 125 mg twice a day for 5 days. In fact, single-day, high-dose famciclovir may double a patient's chances of not progressing to a full outbreak compared with a 5-day course of the medication, presenters suggested at the annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy.

Results from a new multicenter, multinational, randomized, double-blind, placebo controlled study show that when patients with recurrent genital herpes initiated therapy with famciclovir 1 g at the first sign of an outbreak (within 6 hours), the healing time of nonaborted lesions was reduced by 2 days. The median healing time was 4.3 days for 163 patients who received famciclovir compared with 6.1 days for the 166 patients who received placebo.

These data also demonstrated a significantly larger proportion of patients with aborted lesions in the treatment group compared with the placebo group (23.3% vs 12.7%). Famciclovir also reduced the duration of all studied symptoms, including itching, pain, burning, tingling, and tenderness.

"Current standard of care for recurrent genital herpes is 3 or 5 days of oral antiviral therapy. In this study, it is thought that famciclovir was effective in a single-day dose because it provided a full course of therapy up front, when the virus is most active," said lead investigator Fred Aoki, MD, of the University of Man?i?toba, Win?-n?i?peg, Canada.

"This is exciting news for physicians who treat patients with genital herpes, because controlling an outbreak with a single day of treatment has the potential to impact the overall management of recurrent genital herpes," Dr Aoki added.

Side effects from this high-dose, single-day regimen were infrequent, generally mild in severity, and similar to those seen in the placebo group. In clinical trials the most commonly reported adverse events are headache, nausea, and diarrhea.

Patients were instructed to initiate therapy within 6 hours of the onset of prodromal symptoms and/or genital herpes lesions. Patients were then required to return to the clinic within 24 hours of initiating therapy (day 1) and on days 2 and 3. Patients with persistent lesions were asked to return for clinic visits on days 4 and 5, and then every other day until all lesions had healed or until day 14. Healing was defined as loss of all crusts and normalization of the skin. Aborted lesions were defined as herpetic lesions that do not progress beyond the papule stage.

"We seem to be able to give it all in 1 day without any loss of effectiveness and with good tolerance. This is the first time we have been able to give the treatment for 1 day only, so this is a distinct step forward," Dr Aoki told IMWR. "The most important message for doctors is that they are going to have to educate their patients and empower them to treat themselves. Physicians should give them a prescription to take home, so they have the pills in their pocket. They need to take the pills within 6 hours of the start of symptoms of a recurrence."

Based on these findings, Novartis said it is filing a supplemental new drug application with the FDA for a single-day famciclovir treatment indication.?J.S.