Antifungal Activity of Local Anesthetics AgainstCandidaSpecies

[摘要] Objective:To evaluate the activity of benzydamine, lidocaine, and bupivacaine, three drugs withlocal anesthetic activity, againstCandida albicansand non-albicansstrains and to clarify theirmechanism of activity.Methods:The minimal inhibitory concentration (MIC) was determined for 20Candidastrains(18 clinical isolates and two American Type Culture Collection strains). The fungistatic activitywas studied with the fluorescent probe FUN-1 and observation under epifluorescence microscopyand flow cytometry. The fungicidal activity of the three drugs was assayed by viability counts.Membrane alterations induced in the yeast cells were evaluated by staining with propidium iodide,by quantitation of intracellulark+leakage and by transmission electron microscopy of intact yeastcells and prepared spheroplasts.Results:The MIC ranged from 12.5–50.0 μg/mL, 5.0–40.0 mg/mL, and 2.5–10.0 mg/mL forbenzydamine, lidocaine, and bupivacaine, respectively. The inhibitory activity of these concentrationscould be detected with the fluorescent probe FUN-1 after incubation for 60 minutes. A veryfast fungicidal activity was shown by 0.2, 50, and 30 mg/mL of benzydamine, lidocaine, and bupivacaine,respectively.Conclusions:At lower concentrations, the tested drugs have a fungistatic activity, due to yeastmetabolic impairment, while at higher concentrations they are fungicidal, due to direct damage tothe cytoplasmic membrane. Infect. Dis. Obstet. Gynecol. 8:124–137, 2000.

[学科分类] 妇产科学