Melhoria da eficácia do florfenicol no tratamento de pneumonia caprina causada por Pasteurella multocida e Mannheimia haemolytica

Abstract

The objective of the present work is to evaluate the efficacy of the treatment of florfenicol in the traditional dose of 20mg/kg administered intramuscularly and intravenously, in the treatment of pneumonia by Pasteurella multocida and Mannheimia haemolytica, using pharmacokinetic / pharmacodynamic modeling (PK/PD). A Monte Carlo simulation of the pharmacokinetic and pharmacodynamic parameters was carried out, and then the PK / PD modeling was performed to determine the efficacy rates in the treatment of this bacterial infection, according to the minimum inhibitory concentration (MIC) value of the bacteria, considering the range of 0.125 - 4µg/mL. Through the intramuscular route, the probability of reaching the bacteriological eradication rate was 100%, with the MIC up to 0.25µg/mL; bactericidal effect of 100% with MIC up to 0.5µg/mL and bacteriostatic effect of 100% with MIC up to 1µg/mL. Intravenously, the probability of bacteriological eradication was 100% with MIC up to 0.5µg/mL and bacteriostatic effect with probabilities of 100% and 83% with MICs of 2 and 4µg/mL, respectively. Treatment with florfenicol at a dose of 20mg/kg, intramuscularly, decreased significantly for infections caused by microorganisms with MIC greater than 0.5µg/mL, however, intravenously the antibacterial effects were efficient for MICs larger than those of 2 and 4µg/mL (p<0.01). This study highlights the need to incorporate bacteriological isolation into the therapeutic protocol and take into account the route of administration in order to optimize the traditional dose in order to avoid flaws in antimicrobial therapy, enhancing microbial resistance.