PMX-622 (polymyxin B-dextran 70) does not alter in vitro activities of 11 antimicrobial agents.

Because of its capacity to neutralize the lethality of gram-negative bacterial endotoxic lipopolysaccharides, PMX-622 (polymyxin B bound to dextran 70) is being developed for possible adjunctive therapy of gram-negative sepsis. In this study, it was determined that the in vitro antimicrobial activity of PMX-622 was minimal and that it does not interfere with the in vitro antimicrobial activity of 11 antibiotics commonly used to treat gram-negative infections.