Two randomized, double-blind, placebo-controlled studies evaluating the S-Caine Peel for induction of local anesthesia before long-pulsed Nd:YAG laser therapy for leg veins

BACKGROUND. Topical anesthetics are valuable tools for many dermatologic procedures. OBJECTIVE. To evaluate the efficacy and safety of S-Caine Peel composed of 1: 1 (wt: wt) mixture of 7% lidocaine and 7% tetracaine in the induction of local anesthesia before long-pulsed Nd: YAG laser therapy for leg veins. METHODS. Two randomized, double-blinded, placebo-controlled trials were performed. In study 1, 60 adults received S-Caine Peel and placebo cream for 30 or 60 minutes. Efficacy was evaluated by a patient visual analog scale and impression. The pain scale and impression were evaluated by the investigator and an independent observer. In study 2, 40 adults received 60- and 90-minute applications. RESULTS. In study 1, the 30- and 60- minute application times were grouped: Patients had adequate pain relief in 48% of S-Caine sites versus 23% of placebo sites (P<0.001). Investigators reported none-to-mild pain in 50% of active sites versus 33% of placebo sites (P=0.007), with adequate anesthesia in 65% of active sites versus 43% of placebo sites (P=0.002). The independent witness assessed none-to-mild pain in 52% of active sites versus 37% of placebo sites (P=0.067). In study 2, investigators rated none-to-mild pain in 75% of 60-minute and 85% of 90-minute S-Caine sites versus 30% and 50% of placebo sites (P=0.012 and P=0.002, respectively), with adequate anesthesia in 70% and 85% of 60- and 90-minute of active sites versus 25% and 20% of placebo sites (P=0.029 and P=0.001, respectively). The independent witness rated none to mild pain in 80% and 85% of 60 and 90 minute of S-Caine sites versus 35% and 50% of placebo sites (P=0.008 and P=0.004). CONCLUSION. The S-Caine Peel provides safe and highly effective local anesthesia when applied for at least 60 minutes for laser therapy of leg veins. Facile removal of the peel provides a unique advantage and ease in administration.