説明
Caspofungin is the first in a new class of antifungal agents named echinocandin to be
launched in the US for the parenteral treatment of invasive aspergillosis in patients
refractory to, or intolerant of other antifungal therapies such as amphotericin-B1 lipid
formulation of amphotericin-B and/or itraconazole. Caspofungin is a water soluble, stable,
aza-substituted semisynthetic derivative of pneumocandin B, a fermentation product of the
fungus Zalerion arboricola. Since fungi and humans are both eukaryotes, new antifungal
agents must focus on fungus-specific targets in order to minimize potential toxicity in the
human host. In this respect, the lipopeptide caspofungin, inhibits the synthesis of 1,3-beta-
D-glucans present only in the fungal cell wall, which leads to the specific lysis of the
pathogenic cells. The compound is fungicidal rather than fungistatic, an unusual feature
among antifungal agents. Caspofungin has activity in vitro and in vivo against a range of
Candida species (including azole and amphotericin B resistant Candida) and also against
Aspergillus, an important pathogen which is not susceptible to fluconazole. Caspofungin
was generally more active than amphotericin B, flucytosine, fluconazole and itraconazole
against Candida species. Cryptococcus is not susceptible to caspofungin. Caspofungin
has a half-life in human beings around 10 hours. Unlike the azoles, caspofungin does not
inhibit cytochrome P450. The drug has been given intravenously with loading dose of 70
rag, followed by 50 mg daily to be effective in invasive aspergillosis refractory to prior
antifungal therapy. Most of the side effects were mild and comprised fever,
thrombophlebitis, headache, nausea, rash and flushing.