[Studies on the mechanism of antifungal action of ciclopiroxolamine/Inhibition of transmembrane transport of amino acid, K+ and phosphate in Candida albicans cells (author's transl)].

6-Cyclohexyl-1-hydroxy-4-methyl-2(1H)-pyridone, 2-aminoethanol salt (ciclopiroxolamine, Cic, Hoe 296, Batrafen) was fungicidal to growing cultures of Candida albicans, although this effect was apparent after a certain period of cell proliferation, depending upon the drug concentration. Glucose-dependent uptake of all the amino acids tested, K+ and phosphate in starved C. albicans cells was significantly but to a considerably varying extent inhibited by the drug at levels around MIC. Accumulation of amino acid in the cellular pool was more profoundly inhibited than over-all amino acid incorporation into proteins. Cic did not affect the permeability barriers of C. albicans protoplasts or lecithin liposomes. It is presumed from these results that Cic-mediated growth inhibition or death of fungal cells is primarily caused by intracellular depletion of some essential substrates and/or ions, and that such effects are brought about through blockage of their uptake from the medium.