Iontophoretic Application of Acyclovir Gel to Treat Cold Sores

This is a multicenter, placebo controlled, randomized, double blind, subject initiated study of the safety and efficacy of a single, 10-minute, topical iontophoretic application of a novel acyclovir 5% gel for the episodic treatment of recurrent herpes labialis. The design of the trial will also allow the comparison of the efficacy of a single iontophoretic treatment with acyclovir gel within 1 hour of first signs and/or symptoms of a herpetic episode to the efficacy of a single iontophoretic treatment with acyclovir gel 6 to18 hours after first signs and/or symptoms. Approximately 810 subjects will be enrolled to treat about 80 subjects in each of three treatment arms. Depending upon how the subject has been randomized into the trial, the subject will receive either: 1) an iontophoretic treatment with active gel within 1 hour of first signs/and or symptoms, followed 6-18 hours later by a second treatment with placebo gel; 2) an iontophoretic treatment with placebo gel within 1 hour of first signs/and or symptoms, followed 6-18 hours later by a second treatment with active gel; or 3) an iontophoretic treatment with placebo gel within 1 hour of first signs/and or symptoms, followed 6-18 hours later by a second treatment with placebo gel. After being enrolled and randomized into the study, subjects will be sent home with a locked kit containing the iontophoretic device with either active or placebo gel. At first signs and/or symptoms of a recurrent herpetic episode (prodromal or erythema), the lesion will be confirmed by telephone interview with the subject and, upon confirmation of the lesion, the subject will be given the combination to the locked kit and instructed to begin treatment immediately. The subject will then be instructed to return to the clinic within 6 to 18 hours of first signs and/or symptoms for a second iontophoretic treatment, appropriate to the treatment arm into which they have been randomized, and an evaluation. The subject will visit the clinic for daily follow-up evaluations for 3 to 14 days following the first treatment and will be called 2 weeks after their last clinic visit for a final safety evaluation.