Steady-State Plasma Concentration:

• The pharmacologic target for colistin is an average steady-state plasma concentration of 2 mg/L (Css,avg)

Susceptibility Breakpoint:

• The susceptibility breakpoint for colistin for Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter is less than or equal to 2 mg/L

Expressing Colistin Doses:

• Colistin doses in the scientific literature may be expressed in different ways. The conversion is as follows:
  • 1 million International Units of Colistin = 33 mg of Colistin Base Activity (CBA) = 80 mg of colistimethate (CMS)
• All doses for Colistin should be expressed in Colistin Base Activity