Posaconazole is primarily used as an antifungal medication to treat and prevent various fungal infections. It is particularly effective against infections caused by Aspergillus and Candida species, which can be life-threatening in immunocompromised patients, such as those undergoing chemotherapy or organ transplants. The drug is also used to treat oral thrush in HIV/AIDS patients and to manage invasive fungal infections in individuals with weakened immune systems. Posaconazole is available in oral and intravenous forms, providing flexibility in administration based on patient needs. Its broad-spectrum activity and ability to target difficult-to-treat fungal infections make it a critical tool in clinical settings.