Avaliação in vitro da atividade antifúngica da Amiodarona e sua interação farmacológica com Fluconazol frente a Cryptococcus spp

Abstract

Cryptococcosis is a disease caused by pathogenic fungi Cryptococcus neoformans and Cryptococcus gattii, which are yeasts that can infect the lungs, central nervous system and blood. The pathogen C. neoformans is considered a critical priority by the World Health Organization (WHO), generating, together with C. gattii, about 223,100 annual cases and about 181,100 deaths of cryptococcal meningitis in the world. Among the possible causes for the increase in cases and consequent increase in mortality, we can mention the reduced sensitivity of strains of Cryptococcus spp. to the antifungals itraconazole, amphotericin B and fluconazole, which are part of the therapy against cryptococcosis. This situation, there is a search for strategies to circumvent them, such as the repositioning of drugs that aims to use drugs already marketed for the treatment of other diseases, unlike the original indication. Thus, we sought to evaluate the in vitro antifungal activity of the antiarrhythmic drug amiodarone and the pharmacological interaction of this antiarrhythmic drug with fluconazole against clinical strains of Cryptococcus spp. In this study, 7 clinical strains of Cryptococcus spp. and 2 strains from the ATCC bank belonging to the Laboratory of Bioprospection of Antimicrobial Molecules (LABIMAN). To determine the antifungal activity of amiodarone and fluconazole, a sensitivity test was performed using the Broth Microdilution technique according to the CLSI M27-A3 protocol. The determination of the minimum inhibitory concentration (MIC) was made from the visual analysis of the growth of 50% of the microorganism. To determine the pharmacological interaction, the Checkerboard Method was used to calculate the Fractional Inhibitory Concentration Index (ICIF). Regarding the MIC of amiodarone, values between 1 and 256 μg/mL were found and for fluconazole, MIC values between 1 and 32 μg/mL were obtained. About the effect caused by the association of amiodarone and fluconazole, it was found that in 4 strains there was a synergistic interaction and in 3 strains there was an additive interaction. Thus, it is possible to demonstrate the importance of this pharmacological association in vitro, thus encouraging further research into this combination in mice and other drugs in the context of repositioning drugs for inhibiting fungal growth.