Caspofungin is an antifungal medication used primarily to treat serious fungal infections, particularly those caused by Candida and Aspergillus species. It works by inhibiting the synthesis of beta-(1,3)-D-glucan, an essential component of the fungal cell wall, leading to cell death. This medication is typically administered intravenously and is often used in patients who are immunocompromised or have not responded to other antifungal treatments. Common side effects may include fever, rash, and gastrointestinal issues, but it is generally well-tolerated compared to other antifungal agents.