Lack of correlation of 24- vs. 48-h itraconazole minimum inhibitory concentrations with microbiological and survival outcomes in a guinea pig model of disseminated candidiasis

Mycoses. 2010 Sep;53(5):438-42. doi: 10.1111/j.1439-0507.2009.01733.x. Epub 2009 Jun 4.

Abstract

A 'trailing' effect has been commonly observed when azole antifungals are tested against Candida spp. Previous experience with fluconazole indicates that 24-h minimum inhibitory concentration (MIC) values are more compatible endpoints when compared with clinical outcomes. We evaluated the trailing effect of Candida isolates tested with itraconazole in a guinea pig model of systemic candidiasis. Survival and organ burden were only significantly affected by using a higher dose of itraconazole, irrespective of the MIC differences at 24 and 48 h. A fluconazole-resistant strain with susceptible dose-dependent MICs to itraconazole was successfully treated with high-dose itraconazole. Our data suggests that survival and microbiological response depend more on drug dosing than on the trailing phenotype of the isolates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antifungal Agents / administration & dosage
  • Antifungal Agents / pharmacology*
  • Antifungal Agents / therapeutic use
  • Candida albicans / drug effects*
  • Candida albicans / growth & development*
  • Candidiasis / drug therapy*
  • Candidiasis / microbiology
  • Candidiasis / mortality*
  • Colony Count, Microbial
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drug Resistance, Fungal
  • Fluconazole / pharmacology
  • Guinea Pigs
  • Humans
  • Itraconazole / administration & dosage
  • Itraconazole / pharmacology*
  • Itraconazole / therapeutic use
  • Microbial Sensitivity Tests
  • Phenotype
  • Time Factors
  • Treatment Outcome

Substances

  • Antifungal Agents
  • Itraconazole
  • Fluconazole