Lidocaine/tetracaine peel in topical anesthesia prior to laser-assisted hair removal: Phase-II and Phase-III study results

Background: Patient comfort is essential during dermatologic procedures. Objectives: To evaluate anesthetic efficacy in laser-assisted hair removal of a self-occluding topical anesthetic (lidocaine 70mg/g and tetracaine 70mg/g, “LT peel”), which air-dries and can be peeled off 30 min post-application. Methods: Studies A (Phase–II) and B (Phase–III) were randomized, double-blind, placebo-controlled and paired. Applications of LT peel and placebo were concurrent: in Study A, 60 subjects were randomized to 30, 45, or 60-min groups, and in Study B, 50 subjects had 30-min applications. After drug removal, the investigator assessed for erythema, edema, and blanching. Efficacy evaluations followed the procedure: subject's pain [Visual Analog Scale (VAS), no to worst pain (0 – 100)], subject's/investigator's impression of anesthetic adequacy, and investigator's pain ratings. Adverse events (AEs) were recorded. Results: VAS scores were significantly lower (p < 0.05) for LT peel: mean scores were 26.7 for LT Peel vs. 44.3 for placebo (Study A total population, similar between application times) and 23 vs. 31.7 (Study B), respectively. For both studies, subject's/investigator's ratings favored LT peel (p < 0.05 vs. placebo). Mild skin reactions occurred more frequently for LT peel. Conclusions: After a 30-min application, LT peel was effective and well-tolerated in providing anesthesia for laser-assisted hair removal.