Effective treatment of herpes simplex labialis with penciclovir cream: combined results of two trials.

Background: Two randomized, double-blind, parallel-group clinical trials were conducted in Europe and North America to compare the efficacy and safety of topical 1 percent penciclovir cream with a placebo cream.

Methods: A total of 4,573 immunocompetent people with a history of recurrent herpes simplex labialis, or HSL, with three or more episodes a year that typically manifested as classical lesions, were enrolled and prospectively dispensed medication-either 1 percent penciclovir in a cetomacrogol cream base or a matching placebo. Patients self-initiated treatment and were required to apply study medication six times per day for the first day and every two hours while awake for four consecutive days.

Results: Of 4,573 enrolled patients, 3,057 initiated treatment (1,516 with penciclovir and 1,541 with placebo). Combined data from two trials revealed that penciclovir recipients lost classical lesions 31 percent faster than did placebo recipients (hazard ratio, or HR, = 1.31; 95 percent confidence interval, or CI, 1.20 to 1.42; P = .0001) and experienced 28 percent faster resolution of lesion pain (HR = 1.28; 95 percent CI, 1.17 to 1.39; P = .0001). Significant benefits were achieved with penciclovir use whether treatment was initiated in the early stages (P = .001) or later stages (P = .0055).

Conclusions: The largest data set currently available on the treatment of recurrent HSL revealed that penciclovir cream significantly outperformed the placebo in healing classical lesions and resolution of pain.

Clinical Implications: The authors found that penciclovir cream positively affects recurrent HSL, and dose frequency is vital to topical treatment. Even when penciclovir was applied late, it was effective in favorably altering the course of recurrent HSL.