Colistin: still a lifesaver for the 21st century?

INTRODUCTION: Living in the 'era of antibiotic resistance' and facing the threat of an 'end to antibiotics', physicians in the last decade have revived use of colistin, since the available literature at the clinical level was poor and limited Areas covered: Herein, the authors present the current available knowledge regarding colistin, i.e. in vitro activity and interactions, current pharmacokinetics/pharmacodynamics (PK/PD), clinical efficacy against multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria, as well as toxicity issues, whereas the recently published newer plasmid mediated mcr-1 resistance gene is reviewed and discussed. Expert opinion: As proven in a big number of studies and despite their retrospective design, it is surmized that for carbapenemase producing K. pneumoniae, colistin should be given in combination with another active in vitro antibiotic and preferably meropenem/doripenem whenever the relevant minimum inhibitory concentration is ≤8 mg/L. However, colistin monotherapy seems adequate for infections caused by A. baumannii and P. aeruginosa. Based on current knowledge on PK/PD, appropriate dosage schedules are discussed in detail. The worldwide fear of the spread of the plasmid mediated mcr-1 colistin resistance gene is prevailing which, if not limited, the real catastrophy of a life-saver antibiotic will follow soon.