Effect of methotrexate alone and in combination with antifungal drugs on the growth of Candida albicans.

Methotrexate, at concentrations corresponding to drug levels found in vivo, caused a marked reduction in blastospore growth of Candida albicans strains in vitro, but did not affect germ tube elongation during the first 6 h after blastospores were shifted to conditions favouring hyphal formation. Combinations of methotrexate with amphotericin B, flucytosine and itraconazole showed no potentiation or antagonism of the antifungal effect of either component in tests with the blastospore form of C. albicans. In contrast, potentiation occurred when methotrexate-itraconazole combinations were tested for their effect on germ tube elongation of an azole-sensitive strain of C. albicans. This effect was not seen in tests with an azole-resistant strain.