Posaconazole


Posaconazole, sold under the brand name Noxafil among others, is a triazole antifungal medication.
It was approved for medical use in the European Union in October 2005, and in the United States in September 2006. It is available as a generic medication.

Medical uses

Posaconazole is used to treat invasive Aspergillus and Candida infections. It is also used for the treatment of oropharyngeal candidiasis, including OPC refractory to other drugs such as itraconazole and fluconazole.
Clinical evidence of efficacy in treatment of invasive disease caused by Fusarium species is limited.
Intravenous administration appears to be helpful in a mouse model of naegleriasis and the drug kills Acanthamoeba castellanii cysts in vitro.
It has been used to treat mucormycosis caused by Rhizopus mold.

Pharmacology

Pharmacodynamics

Posaconazole works by disrupting the functions of certain membrane-bound enzyme systems, thus inhibiting growth of the fungi. It does this by blocking the synthesis and turnover of the eukaryotic cell membrane component ergosterol by inhibiting an enzyme in this pathway known as CYP51. Posaconazole is significantly more potent at binding to CYP51 than itraconazole.

Microbiology

Posaconazole is active against the following microorganisms:
  • Candida spp.
  • Aspergillus spp.
  • Zygomycetes spp.

    Pharmacokinetics

Posaconazole is absorbed within three to five hours. It is predominantly eliminated through the liver, and has a half-life of about 35 hours. Oral administration of posaconazole taken with a high-fat meal exceeds 90% bioavailability and increases the concentration by four times compared to fasting state.