Micafungin is an antifungal medication used primarily 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 beta-(1,3)-D-glucan, an essential component of the fungal cell wall. This medication is typically administered intravenously and is often used in patients with weakened immune systems, such as those undergoing chemotherapy or organ transplantation. Common side effects may include fever, headache, and gastrointestinal disturbances, but it is generally well-tolerated.