Micafungin is an antifungal medication used to treat serious fungal infections, particularly those caused by Candida species and Aspergillus species. It belongs to a class of drugs known as echinocandins, which work by inhibiting the synthesis of glucan in the fungal cell wall, leading to cell death. This medication is typically administered intravenously and is often used in patients with weakened immune systems, such as those undergoing chemotherapy or organ transplants. Common side effects may include fever, headache, and gastrointestinal issues, but it is generally well-tolerated.