Introduction: Needle infi ltration 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 infi ltrative 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 effi cient and comfortable method for promoting local anesthesia in the surgical approach of pediatric, hyperalgic, or needlephobic patients.

Keywords: ANESTHESIA, LIDOCAINE, AMBULATORY SURGICAL PROCEDURES, IONTOPHORESIS

Introduction: The use of topical anesthetics, has increased in recent years.While they are undoubtedly useful when recommended appropriately by a dermatologist, the improper use of topical anesthetics may result in complications, mainly due to inadequately applying them to wounded or inflamed skin; use on large areas of the body or mucus membranes; or use by high-risk patients. Adverse reactions can include transient local effects, allergic and/or irritative reactions, or more severe (though rare) effects, such as methemoglobinemia, arrhythmias, and cardiorespiratory failure. This paper discusses the commercial formulations of topical anesthetics currently available, their history, pharmacology, clinical use, and potential side effects.

Keywords: ANESTHETICS, ANALGESIA, LIDOCAINE, PRILOCAINE, TETRACAINE

Introdução: The increase in the demand for cosmetic procedures has in turn stimulated the search for effective and safe analgesia.Topical anesthetics are an alternative to infiltrative anesthesia, and promote an appropriate analgesia without inducing adverse effects. Objective: To compare the pain ratings of two topical lidocaine formulations in patients undergoing fractional CO2 laser therapy. Methods: Eight patients underwent a single fractional CO2 laser session after applying a commercial formulation of 4% lidocaine on the right side of the face and a dispensed 30% lidocaine formulation combined with 7% tetracaine on the left side of the face.The intensity of the pain was assessed using the visual analogue pain intensity scale at the end of the procedure. Results: No significant statistical differences were detected between the formulations. Conclusions: Formulations with high concentrations of anesthetics are not more effective than commercial products in producing analgesia.

Keywords: ANESTHETICS, ANESTHESIA AND ANALGESIA, LASERS

Introduction: For some patients, pain during the injection of botulinum toxin can represent a limitation for performing the procedure. There are doubts about whether the use of topical anesthetic decreases pain or interferes with the treatment's efficacy and duration of effect. Objectives: To study the effect of 4% lidocaine cream in controlling pain during BoNT-A - Speywood Unit botulinum toxin application, comparing it to the vehicle. In addition, the study was aimed at verifying whether the cream influences the treatment's outcome and duration. Methods: An experimental, prospective, double-blind, randomized study was carried out. The pain was assessed through a compartmentalized numerical rating scale (CNRS). The effect was assessed through a four-point contraction qualitative scale. Results: After evaluating the pain scale, higher values were observed in the placebo group when compared to the group that used anesthetic, with statistical significance. Furthermore, there was no statistical difference in the efficacy and duration of effect over weeks 4, 8, 12, and 16. Conclusions: BoNT-A - Speywood Unit toxin was effective and safe for the treatment of glabellar and frontal wrinkles. The use of topical anesthetics (4% lidocaine cream) reduced the pain during the procedure. In addition, there was no interference in the toxin's efficacy and effect duration.

Keywords: BOTULINUM TOXIN TYPE A, LIDOCAINE, PAIN, THERAPY.

Deep phenol chemical peeling with the Baker-Gordon formula is indicated for the treatment of severe facial aging. A review of pertinent literature on its main limiting factor-pain-was carried out with searches on two databases (PubMed and Cochrane Library) using the following keywords: chemexfoliation, peel, peeling, and phenol, also cross-referencing with the terms anesthesia and analgesia. The search resulted in 151 articles that contributed little to clarifying what would be the ideal approach for managing pain when using a deep chemical peel with the Baker-Gordon formula. As a result, for this procedure, the authors basically relied on the expert experience-in this case, that of the anesthesiologist-which has been described. Therefore, further studies should be carried out in order to achieve a higher level of scientific evidence.

Keywords: CHEMEXFOLIATION; PHENOL; ANESTHESIA; ANALGESIA.

Introduction: Standard dilution of botulinum toxin is performed with 0.9% saline solution. Some studies show that when diluted in lidocaine and epinephrine, the toxin preserves its function without compromising effectiveness or safety.
Objective: To establish whether the paralyzing effect of ona-toxin type A reconstituted in anesthetic (2% lidocaine) and vasoconstrictor agent (1: 50,000 epinephrine) is as effective as that of the same toxin reconstituted in saline solution, at 48 hours, 1 week, 2, 4, 12 and 24 weeks, for the treatment of periocular lines. To compare the tolerance to pain between the two reconstitution alternatives.
Methods: Fifteen patients with periocular wrinkles were randomized to receive onabotulinum toxin diluted in lidocaine with epinephrine or in saline. Re-evaluations were carried out in 48 hours, 1 week, 2, 4, 12 and 24 weeks.
Results: The data indicate that there was no difference in the symmetry and durability of the botulinum toxin, nor in the pain during the application.
Conclusions: There was no statistically significant difference in the frequency of lateral periocular muscle paralysis and symmetry resulting from the applications of onabotulinum toxin reconstituted in lidocaine with epinephrine or in saline solution. This outcome is consistent with those of previous studies.

Keywords: BOTULINUM TOXINS, TYPE A; DILUTION; LIDOCAINE