Polymyxin B clinical outcomes: A prospective study of patients undergoing intravenous treatment.

WHAT IS KNOWN AND OBJECTIVE: Polymyxins, especially polymyxin B, has become the last line of therapy against Gram-negative pathogens' carbapenemase producers. However, given increasing use of polymyxin B in clinical settings its therapeutic value has been evaluated worldwide due to its toxic effects. The aim of this study was to assess the efficacy and safety of antimicrobial therapy with polymyxin B in patients with multidrug-resistant bacteria in Brazil. METHODS: This was a prospective cohort study in a 403-bed academic tertiary care centre, located in the countryside of Brazil. Patients receiving polymyxin B intravenous treatment for at least 72 hours were eligible for the study. Antimicrobial susceptibility, adverse reactions and clinical outcomes were submitted for descriptive analysis. Main outcomes measure the following: Patients' conditions following treatment (Treatment Success, Mortality, Treatment Failure, Inadequate Empiric Treatment or Indeterminate Response) and toxicities induced by polymyxin B (nephrotoxicity and skin hyperpigmentation). RESULTS AND DISCUSSION: Among 247 patients, treatment success was achieved in 25.1%, while mortality was observed in 32.8%. Empirical therapy was prescribed for 26.3% of the patients. Nephrotoxicity was reported in 40.5%. The carbapenemase producer, Klebsiella pneumonia, was the bacterium most associated with mortality (22.2%). CONCLUSIONS: Even though polymyxin B is currently the main therapy against carbapenemase producers, its use demands robust criteria to lead to positive clinical outcomes.

Brazil's resolutions to regulate the sale of antibiotics: Impact on consumption and Escherichia coli resistance rates.

OBJECTIVE: The aim of this study was to determine the impact of two resolutions to restrict antibiotic use (RDCs no. 44/2010 and 20/2011) in the Campinas metropolitan area (Sao Paulo, Brazil) on antibiotic consumption, resistance rates, and trends in Escherichia coli-causing community-acquired urinary tract infection (UTI). METHODS: The annual retail sale information of antibiotics from drugstores in the Campinas metropolitan area between 2008 and 2012 were obtained through the Intercontinental Medical Statistics Health of Brazil. The daily-defined dose (DDD)/1000 inhabitants/day was calculated from these data to measure consumption. To examine resistance rates, we performed an observational retrospective study in a Campinas teaching hospital, where urinary cultures from outpatients with a clinical suspicion of UTI between October 2009 and September 2015 were analyzed. RESULTS: We observed an increase in rates of antibiotic sales from 2008 to 2011 (cephalosporin: 216.8%, quinolones: 170.9%, aminopenicillins: 140.9%), followed by a decrease in sales in 2012 (cephalosporin: 19.4%, quinolones: 12.7%, aminopenicillins: 11.1%). Sale of nitrofurans, however, did not significantly change during this period. In the retrospective analysis, we observed a significant increasing trend of E. coli resistance for all antibiotic classes, except nitrofurans and folate pathway inhibitors. CONCLUSIONS: We found changes in antibiotic consumption, with an initial increase, followed by a decrease in sales after implementation of the resolutions. However, bacterial resistance does not appear to be affected by the RDCs.