Randomized , double - blind controlled topical anesthesia induced

Submitted on: 06/20/2009 Approved on: 09/10/2009 We declare no confl ict of interest. aBStRaCt Introduction: Needle infiltration of local anesthetic is a painful procedure, thus, a topical anesthetic is a comfortable alternative. However, it is difficult to deliver transcutaneous polar drugs. Iontophoresis is a noninvasive technique that uses electrical current for releasing electrically charged drugs through biological membranes. Objective: To evaluate the anesthesia induced by iontophoresis of lidocaine for a standardized painful stimulus. Material and methods: Randomized, controlled, double-blind study, involving 10 volunteers under the anesthetic effects of topical application of lidocaine gel 2% and noradrenaline 1:50.000, with or without iontophoresis of 1.85 milliamps for 13 minutes. Pain sensitivity was evaluated by the prick of a 21G needle in the arms posterior region, using a visual numerical scale. Results: Patients mean age was 50.8 ± 11.4 years. Nine of them were women. All had previously received infiltrative anesthesia. Iontophoresis was well tolerated by volunteers. The median pain scores were 0 and 3 for the arm that received the iontophoresis and for the one that did not receive, respectively (p < 0.01). Conclusion: The anesthetic effect in the region subjected to iontophoresis suggests an efficient and comfortable method for promoting local anesthesia in the surgical approach of pediatric, hyperalgic, or needle-phobic patients.