In vitro activity of posaconazole against clinical isolates of dermatophytes.

A broth macrodilution method following the recommendations established by the National Committee for Clinical Laboratory Standards was used to compare the in vitro activity of posaconazole (PCZ) with that of itraconazole (ITC) against 30 clinical isolates of dermatophytes belonging to six different species. In terms of MICs, PCZ showed an activity equal to that of ITC. MICs of PCZ at which 50% (MIC(50)) and 90% (MIC(90)) of the isolates were inhibited were 0.5 and > 4.0 microg/ml, respectively. The MIC(50) and MIC(90) of ITC were 1.0 and > 4.0 microg/ml, respectively. However, PCZ showed a more potent fungicidal activity than that of ITC against isolates belonging to the genus Microsporum (P = 0.03). PCZ merits further investigation as a potentially useful agent for treatment of dermatophytosis.