Used primarily as an antifungal medication, especially in the treatment of serious yeast infections such as cryptococcal meningitis and candidiasis. It is often administered in combination with other antifungals like amphotericin B to enhance effectiveness and reduce the risk of resistance. Its selective toxicity makes it effective against fungal cells while sparing human cells, as it is converted into active metabolites only within fungal organisms. Also used in research settings as a selection agent in molecular biology and genetic engineering systems.