infectious diseases
Polypeptide Antibiotics: Bacitracin, Colistin, Polymyxin B
Dosing Considerations for Polypeptide Antibiotics
Because colistin was released before the advent of modern pharmacokinetic/pharmacodynamic analysis, appropriate dosing has not been studied as rigorously as for many modern antibiotics. In addition, manufacturers do not use a uniform method of describing drug amount; some use international units, and others use milligrams of colistin base activity or milligrams of actual colistimethate. Whatever units are used, many experts believe that the manufacturer-recommended dose of 2.5 to 5 mg/kg of colistin base activity per day divided into 2 to 4 doses is too low and recommend higher dosing regimens, including the use of a loading dose ( Dosing considerations reference ). However, nephrotoxicity is dose-dependent and becomes a greater concern with higher doses. Dosing should be discussed with an expert. 1.Nation RL, Garonzik SM, Thamlikitkul V, et al: Dosing guidance for intravenous colistin in critically-ill patients.Clin Infect Dis64:565–571, 2017. doi: 10.1093/cid/ciw839 