Penciclovir cream for the treatment of sunlight-induced herpes simplex labialis: A randomized, double-blind, placebo-controlled trial

Objective: The purpose of this study was to further define the therapeutic value of penciclovir cream in the treatment of sunlight-induced herpes labi alis by comparing its efficacy and tolerability with those of an inactive c ontrol (purified water). Methods: In this randomized, double-blind, placebo-controlled, parallel-gro up clinical trial, lesions were induced by exposure to sunlight. Treatment was self-initiated within 1 hour of development of the signs or symptoms of a recurrence. Results: Healthy male and female patients (mean age, 38.3 years; range, 18 to 81 years) who had a history of sunlight-induced herpes labialis (mean of 6 recurrences in previous 12 months) applied either penciclovir cream (n = 266) or purified water (n = 275). Penciclovir cream significantly decrease d the time to lesion healing (P < 0.001), with a reduction in median time o f up to 2 days. The efficacy of penciclovir cream was further supported by a significant reduction in maximum lesion area (P = 0.008), a faster loss o f lesion-associated symptoms (P = 0.026), and significant reductions in dai ly assessments of pain (P less than or equal to 0.040), itching (P less tha n or equal to 0.032), burning (P less than or equal to 0.028), and tenderne ss (P less than or equal to 0.026) as moderate or severe. These effects wer e reinforced by the results of the daily self-assessment of lesion attribut es, with significantly fewer severe/extreme assessments of lesion size (P l ess than or equal to 0.003), noticeability (P less than or equal to 0.003), amount of scab/crust (P less than or equal to 0.003), raised/ swollen area (P less than or equal to 0.040), soreness/tenderness (P less than or equal to 0.043), and overall severity (P less than or equal to 0.001) throughout the study period. Conclusions: Penciclovir cream has demonstrated efficacy for a bread range of clinically important outcomes. Significant effects on lesion area, lesio n symptoms, and other lesion attributes extend the clinical efficacy of pen ciclovir cream beyond lesion healing.