antibioticsbooks

chapter 29 Azoles 191
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Important Facts
• Voriconazole is active against many fluconazoleresistant
strains of Candida albicans, but it
is less active against them than fluconazolesusceptible
strains. An echinocandin is a better
choice, but consider susceptibility testing if you
need to use voriconazole for an oral option.
• Voriconazole is a potent inhibitor and a substrate
of the cytochrome P450 system. The list
of drugs that interact with voriconazole is long
and varied. Some of them are contraindicated,
such as rifampin, while others, such as calcineurin
inhibitors (e.g., cyclosporine), require
dose adjustments. This is significant because
many of the patients who require voriconazole
are immunosuppressed.
• The IV form of voriconazole contains a cyclodextrin
vehicle that accumulates in renal
dysfunction and may be nephrotoxic. It is contraindicated
with a creatinine clearance of less
than 50 ml/min. The oral formulations avoid
this issue.
• Voriconazole is eliminated hepatically and
is unlikely to be useful in the treatment of
candiduria.
What It’s Good For
Voriconazole is the drug of choice for invasive
aspergillosis and is frequently used in the treatment
of infections caused by other molds. It can be
used for candidiasis as well, but fluconazole and
echinocandins are more frequently used for these
infections. Some clinicians use voriconazole in the
empiric treatment of febrile neutropenia.