Amphotericin B drug molecule. Ball-and-stick molecular model of amphotericin B, an antifungal drug. It is used to treat serious fungal infections, such as leishmaniasis. It is typically administered via intravenous injection. It has extensive side-effects and so its use is usually limited to only critically ill or immunocompromised patients. Its chemical formula is C47H73NO17. Atoms are represented as spheres with conventional colour coding: carbon (black), oxygen (red), and nitrogen (blue).