The Toxicity of Chlorhexidins on Mammalian Connective Tissue and Vasculature

Abstract

During one episode in the British quest for antimalarial agents a class of compounds was discovered to have antibacterial activity. Investigators at Imperial Chemical Industries Ltd., Manchester, England found that certain bisbiguanides, especially chlorhexidine, were effective in this latter respect. | Bisbiguanide compounds were examined extensively at ICI from the late nineteen forties but the results of these investigations were not published until 1954 when G.E. Davies et.al. reported the bacteriostatic, bactericidal and toxic effects of chlorhexidine. Both gram positive and gram negative bacteria were susceptible but only a very weak action against bacterial spores was observed. Action against hemolytic streptococci in infected artificial wounds was good. Attempts to establish resistant bacterial strains were unsuccessful with their experimental methods. In mice extremely low oral toxicity (LD50 2,000 mg/kg) was found although intravenous toxicity (LD50 25 mg/kg) was comparatively high. There was no interference with phagocytosis of staphylococci by human leucocytes in vitro.