Fungal infections have been increasingly reported in routine, especially opportunistic ones such as aspergillosis, which represents a serious challenge for health professionals. The use of itraconazole, for a long time, was effective for a good clinical response, but factors associated with the advancement of medicine, length of stay, diagnostic errors, incorrect doses, and wrong choice of antifungal classes favored the appearance of resistance mechanisms. Thus, new research, together with the development of new molecules, is being carried out in order to reduce the advance of resistance, increasing patient survival.