Brian T. Tsuji, PharmD, from the University at Buffalo in New York, and colleagues report on consensus therapeutic guidelines for agent selection and dosing of polymyxin antibiotics for optimal use in adults. To make therapeutic recommendations, a diverse international panel of experts was established.
The authors note that since reintroduction of polymyxin into the clinic in the 1980s, there has been confusion regarding their use due to differences in the formulations. Standard broth microdilution ISO-74 20776 should be used as the reference method for the minimum inhibitory concentration testing of colistin. Sulphate salts of polymyxins must be used; agar dilution, disk diffusion, and gradient diffusion are not recommended. The target average steady-state plasma concentration is about 2mg/L for total drug for colistin, with a similar target for polymyxin B (2 to 4mg/L). Polymyxin B is recommended as the preferred agent for routine systemic use in invasive infections; colistin is preferred for treatment of lower urinary tract infections. In patients receiving colistin or polymyxin B, concomitant nephrotoxic agents should be avoided.
“These guidelines represent consensus recommendations from expert clinicians and scientists around the globe to guide polymyxin therapy in Gram-negative infections where no treatments appear to exist,” Tsuji said in a statement.
Several authors disclosed financial ties to the pharmaceutical industry.