Caspofungin

Caspofungin is an antifungal medication in the echinocandin class. It is used to treat invasive fungal infections, particularly those caused by Candida species, including candidemia and esophageal candidiasis, and it may be used as salvage therapy for invasive aspergillosis in patients who have not responded to or cannot tolerate other treatments. It is administered intravenously in a hospital setting.

The drug works by inhibiting the enzyme 1,3-beta-D-glucan synthase, which is essential for synthesizing beta-1,3-D-glucan, a key component of the fungal cell wall. Inhibition weakens the cell wall, leading to osmotic instability and fungal cell death. Caspofungin has good activity against most Candida species, but activity can be reduced against Candida parapsilosis and it has limited activity against Cryptococcus and certain molds.

In adults, the usual dosing is an initial loading dose of 70 mg IV on day 1, followed by 50 mg IV daily. Dosing may be adjusted for patients with hepatic impairment, and treatment is only given by intravenous infusion. The drug is metabolized primarily by hydrolysis and excretion is mainly non-renal. Caspofungin is not expected to interact substantially with cytochrome P450 enzymes, but coadministration with cyclosporine can increase caspofungin exposure, and rifampin may reduce its levels.

Common adverse effects include fever, rash, histamine-mediated infusion reactions, nausea, vomiting, and elevations in liver enzymes. Serious liver injury and hypersensitivity reactions are possible, though rare. Susceptibility to resistance can arise through mutations in the FKS genes, and cross-resistance among echinocandins has been reported.