Polymyxin B and Colistin

GRAM-negative bacilli, in particular pseudomonas species, are of increasing concern to the clinician as infectious and therapeutic problems.1 , 2 Accordingly, polymyxin B has grown to singular importance as its utility to the treatment of systemic infections caused by pseudomonas species has been appreciated and exploited.In 1961 colistin was introduced as an agent that supposedly retained the antibacterial merit of polymyxin B in a polypeptide compound of lesser inherent nephrotoxic liability. From the outset, the striking pharmacologic and chemical similarities of colistin to the entire polymyxin group of antibiotics, including polymyxin B, were recognized.3 4 5 6 However, critical comparison of these agents, taking . . .