Our recent study showed that the simultaneous application of clotrimazole with CdCI2 or PbCI2 exerted potent cytotoxic action in rat thymocytes although respective agents were ineffective. It was also the case of ZnCl2 and clotrimazole in preliminary study using rat thymocytes. Since clotrimazole is supposed to be a candidate for anticancer drug, we examined the effects of clotrimazole, ZnCI2, and their combination on human leukemia K562 cells. The combination of clotrimazole and ZnCl2 exerted potent cytotoxic effects on the growth and lethality of K562 cells by presumably modifying the process of cell death. The result suggests the possibility that endogenous Zn2+ may modify the action of clotrimazole
