A single day of famciclovir started within 6 hours of a genital herpes outbreak shortens the duration of recurrent genital herpes lesions, said Fred Y. Aoki, MD, at the 45th ICAAC meeting in Washington, DC.

The study was "another step in the evolution of treatment for episodic genital herpes, as researchers investigate shorter and shorter treatment times," he said. Before this study, success was demonstrated with a 3-day regimen of valacyclovir (500 mg bid) and a 2-day regimen of acyclovir (800 mg tid).

In the double-blind study, 329 patients with recurrent genital herpes were randomized to either famciclovir, 1 g twice orally or placebo for a single day. To be eligible, patients had to have 4 or more episodes in the preceding 12 months. More than 20% of patients in each group had been on suppressive therapy during the previous 12 months.

The proportion of patients with aborted lesions on an intent-to-treat analysis was 12.7% in the placebo group and 23.3% in the famciclovir group (P=.003). Among patients with lesions that were positive by polymerase chain reaction, the proportion with aborted lesions was 5.3% in the placebo group and 20.9% in the famciclovir group (P<.001).

Famciclovir significantly reduced the time to healing of nonaborted lesions by 2 days (median time: 4.3 d vs 6.1 d; P<.001).

The time to resolution of all studied symptoms (itching, pain, tingling, tenderness) was reduced by 39% (median time: 3.3 d vs 5.4 d; P<.001) in the famciclovir recipients relative to the placebo recipients.

Drug-related adverse events occurred in 13% of patients randomized to famciclovir and 9% of patients randomized to placebo. The reported adverse events were infrequent and mostly of mild-to-moderate severity.

Headache was the most-frequent adverse event in the famciclovir group (14%). Headaches were mostly of mild-to-moderate severity, occurred 1 or 2 days after the first dose of study medication, and lasted 1 to 3 days. Most patients with headaches took concomitant medication to resolve them. Prior to the study medication, headache occurred in 3.7% of famciclovir patients and 0.6% of placebo patients.

Having patients initiate therapy is practical since most are aware when recurrences are starting, Dr Aoki said. "The median time to starting therapy was 2 hours within symptom onset, which was better than anticipated," he said.