Does Lidocaine Have Antimicrobial Effects Against Major Pathogens That Infect Wounds? An in Vitro Study

Abstract

Local anesthetics are commonly used in medicine and dentistryand have a low cost, but their action as a microbicidalagent is still controversial. This study aimed to evaluate the antimicrobial effects of lidocaine against bacteria thatmost commonly infect surgical wounds. We evaluated Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Proteus mirabilisand Enterococcus faecalis. The solutions tested were saline, chlorhexidine, lidocaine (solution and pure) and an antibioticsolution. The agar diffusion test was performedusingPetri dishes. The agar plates were made in duplicate and incubated in an oven at 37°C for 48h. Subsequently, the inhibition halos were measured.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 thetested bacteria. However, the antibiotic solution and the chlorhexidine inhibited the growth of all bacteria.