Amphotericin B is an antifungal medication used to treat serious fungal infections. It works by binding to the cell membranes of fungi, causing them to become leaky and ultimately leading to cell death. This drug is often used in patients with weakened immune systems, such as those with HIV/AIDS or undergoing chemotherapy. Typically administered intravenously, amphotericin B can have side effects, including fever, chills, and kidney damage. Due to its potential toxicity, doctors carefully monitor patients receiving this treatment. It is considered a critical option for life-threatening fungal infections, especially those caused by Candida and Aspergillus species.