Amphotericin B is primarily used as an antifungal medication to treat serious fungal infections. It is particularly effective against systemic infections caused by fungi such as Candida, Aspergillus, and Cryptococcus. This drug is often administered intravenously for conditions like cryptococcal meningitis, fungal infections in immunocompromised patients, and severe cases of candidiasis. Additionally, it is used in the treatment of leishmaniasis, a parasitic infection caused by Leishmania species, in some cases. Due to its broad-spectrum antifungal activity, it is considered a critical treatment option for life-threatening fungal infections. However, its use is often limited by potential side effects, including kidney toxicity, which requires careful monitoring during therapy. In some cases, it is used in combination with other antifungal agents to enhance efficacy or reduce resistance.