Benzyl Alcohol as an Alternative Local Anesthetic☆☆☆

Abstract 

Study Objectives: Benzyl alcohol has been used as a local anesthetic for brief superficial skin procedures; however, its efficacy for long-term cutaneous anesthesia has not been established. We sought to compare the cutaneous anesthetic effects of benzyl alcohol with epinephrine with the effects of lidocaine with epinephrine and with placebo. Methods: This study was a prospective, randomized, double-blind, placebo-controlled clinical trial of 30 healthy paid adult volunteers. Subjects received 1-mL intradermal injections of benzyl alcohol .9% with 1:100,000 epinephrine, lidocaine 1% with 1:100,000 epinephrine, and physiologic saline solution without benzyl alcohol as placebo in a randomized, double-blind fashion. Pain on injection and degree of anesthesia at 5, 15, 30, and 45 minutes was assessed with a 10-cm graded visual analog scale (VAS). Statistical significance was determined by repeated measures ANOVA between groups with a Neuman-Keuls test for post hoc comparison of means and Student’s t test for paired means. Results: Benzyl alcohol was 48% less painful on injection than placebo (P <.008) and 42% less painful on injection than lidocaine with epinephrine (P <.05). Lidocaine with epinephrine and placebo were equally painful on injection. After the 5-minute measurement, benzyl alcohol provided significantly better anesthesia than placebo during the remaining observation period (VAS score 48%, 49%, and 51% decreased from baseline at 15, 30, and 45 minutes, respectively, all P <.02 versus placebo). However, benzyl alcohol provided less effective anesthesia than lidocaine with epinephrine (VAS score 72%, 76%, 84%, and 88% decreased from baseline at 5, 15, 30, and 45 minutes, respectively, all P <.001 versus placebo) throughout most of the observation period. Conclusion: Benzyl alcohol with epinephrine provides prolonged cutaneous anesthesia, although it is not as effective as lidocaine with epinephrine. However, benzyl alcohol is significantly less painful on injection than lidocaine with epinephrine, and it may offer an alternative for local anesthesia. [Wilson L, Martin S: Benzyl alcohol as an alternative local anesthetic. Ann Emerg Med May 1999;33:495-499.]