Table 3:
Antifungal Agents
Caspofungin (Cancidas)
Voriconazole (Vfend)
Mechanism
of action		 Inhibition of 1,3-ß-D-glucan synthase Inhibition of fungal cyctochrome P-450-dependent 14-α-demethylase
Spectrum
of activity		 Aspergillus sp, C albicans, C glabrata, C tropicalis, C krusei, C parapsilosis, and C lusitaniae; not active against Cryptococcus Aspergillus sp, C albicans, C glabrata, C tropicalis, C krusei, C parapsilosis, and C lusitaniae; may be active against Cryptococcus, endemic fungi, and Fusarium sp
Oral absorption <1% >80 %
Metabolism Metabolized by hydrolysis and N-acetylation; does not appear to be a substrate for the CYP-450 system CYP 2C9 and CYP 2C19
Half-life ß-phase half-life is 9-11 hours; an additional longer-phase half-life of 40-50 hours also occurs Approximately 6 hours
Adverse
reactions		 Fever, rash, nausea, vomiting, and phlebitis at the injection site Visual changes, increased liver function test results, and rash
Potential drug interactions Contraindicated with cyclosporine; tacrolimus levels decreased by 30% Rifampin, rifabutin, and phenytoin, carbamazepine may decrease voriconazole levels. Cyclosporine levels are increased. Potential for interaction with any medication metabolized via 2C9, 2C19, or 3A4
Other
considerations		 Pregnancy category C. Do not use diluents containing dextrose Hepatotoxicity appears to be level-related, and levels can vary greatly between patients at standard doses
Approved
indications

Treatment of invasive aspergillosis in patients who are refractory to or intolerant of other therapies.

Caspofungin has not been studied as initial therapy for invasive aspergillosis

Pending FDA approval
Dosage and administration Day 1: 70 mg IV x 1 dose, then 50 mg IV q24h*

Aspergillus or invasive mold infections^
6 mg/kg IV q12h the first 24 hours, then 4 mg/kg IV q12h or 400 mg PO q12h x 2 doses, then 200 mg PO q12h

Candida infections^
6 mg/kg IV q12h the first 24 hours, then 3 mg/kg IV q12h or 400 mg PO q12h x 2 doses, then 200 mg PO q12h

*Dosage reduction is for patients with hepatic insufficiency; see package insert;
^Proposed doses, may require dose adjustment based on levels or concurrent medications
Copyright 2002 The Cleveland Clinic Foundation

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