In vitro synergy with fluconazole plus doxycycline or tigecycline against clinical Candida glabrata isolates

Med Mycol. 2019 Jan 1;57(1):122-126. doi: 10.1093/mmy/myy008.


Candida species, traditionally viewed as opportunistic agents, are increasingly seen as a cause of infection in hospitalized patients. Treatment options are limited to a few classes of drugs. Increased resistance, especially by Candida glabrata, is problematic. We investigated the interaction between fluconazole and doxycycline or tigecycline, using clinically unique blood culture C. glabrata isolates. Eighteen isolates were screened using an Etest® MIC:MIC synergy method. With the doxycycline plus fluconazole combination, 28% of isolates showed synergy; tigecycline plus fluconazole showed 94% synergy. No antagonism was seen. The mechanisms of these interactions are unclear. Further research is warranted to assess clinical utility.

MeSH terms

  • Antifungal Agents / pharmacology
  • Candida glabrata / drug effects*
  • Candida glabrata / isolation & purification
  • Candidemia / microbiology
  • Doxycycline / pharmacology*
  • Drug Resistance, Fungal / drug effects*
  • Drug Synergism
  • Fluconazole / pharmacology*
  • Humans
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Tigecycline / pharmacology


  • Antifungal Agents
  • Tigecycline
  • Fluconazole
  • Doxycycline