THE PARTICIPATION OF POLYMYXIN B IN COMBINED ANTIBIOTIC ACTION

Abstract

Polymyxin B can participate in antibiotic synergism against Gram-negative bacilli. As compared to other drugs, polymyxin B enters into such combinations relatively infrequently. Coliform bacilli respond to the synergistic effects of polymyxin B with other antibiotics, particularly the tetracyclines, chloramphenicol, or streptomycin, much more commonly than Pseudomonas, Proteus or Salmonella. Clinical cases are reported in which the combination of polymyxin B with another antibiotic gave in vitro synergism, and thus permitted the admn. of much smaller, less expensive, and safer doses of polymyxin B in effective combined therapy than would have been possible if this drug had been used alone.