DOES LIDOCAINE HAVE ANTIMICROBIAL EFFECTS AGAINST MAJOR PATHOGENS THAT INFECT WOUNDS? AN “IN VITRO” STUDY

Abstract

Local anesthetics are commonly used in medicine and dentistry and have a low cost, but their action as a microbicidal agent is still controversial. This study aimed to evaluate the antimicrobial effects of lidocaine against bacteria that most commonly infect surgical wounds. We evaluated Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Proteus mirabilis and Enterococcus faecalis. The solutions tested were saline, chlorhexidine, lidocaine (solution and pure) and an antibiotic solution. The agar diffusion test was performed using Petri dishes. The plates tested with lidocaine (pure or solution) presented no inhibition halo. The antibiotic solution presented the largest inhibition halos for all the bacteria (p < 0.05). Chlorhexidine formed an inhibition halo similar to that of the antibiotic solution for Escherichia coli (p > 0.05). Lidocaine did not present an antimicrobial effect for any of the tested bacteria. However, the antibiotic solution and the chlorhexidine inhibited the growth of all bacteria.