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Antifungal Susceptibility Test Interpretive Criteria

This web page provides information about the in vitro susceptibility of fungi to certain drugs.

The safety and efficacy of these drugs in treating clinical infections due to such fungi may not have been established in adequate and well-controlled clinical trials and the clinical significance of such susceptibility information in those instances is unknown.

The approved product labeling for specific drugs provides the uses for which the product is approved.

Labeling for these products can be found at Drugs@FDA or FDA Online Label Repository.

Recognized Standards

The table below lists antifungal drugs and indicates which, if any, susceptibility test interpretive criteria, also known as “breakpoints” (abbreviated as STIC), are recognized or identified by FDA for that drug.

With certain exceptions and additions, identified in the table, FDA recognizes the standards:

  • Clinical and Laboratory Standards Institute (CLSI). Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts; Fourth Informational Supplement. CLSI document M27-S4 (2012). Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 2500, Wayne, Pennsylvania 19087, USA. (CLSI M27-S4)
  • Clinical and Laboratory Standards Institute (CLSI). Method for Antifungal Disk Diffusion Susceptibility Testing of Yeasts; Approved Guideline – Second Edition. CLSI document M44-S3 (2009). Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 500, Wayne, Pennsylvania 19087, USA. (CLSI M44-S3)

If the table indicates that STIC for a drug are included in CLSI M100 and there are no additions or exceptions, CLSI M100 contains all of the STIC recognized by FDA for that drug.

For specific drug/yeast combinations, FDA recognizes in part the standards published in:

  • Clinical and Laboratory Standards Institute (CLSI). Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts; Fourth Informational Supplement. CLSI document M27-S3 (2008). Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 2500, Wayne, Pennsylvania 19087, USA. (CLSI M27-S3)

If this standard is recognized in part, that information is provided in the hyperlinked information for the specific drug listed in the table below.

FDA recognition of STIC standard(s) for a drug does not include recognition of epidemiological cutoff values (ECVs) for that drug.

Exceptions or Additions to the Recognized Standards of CLSI M27-S4 and CLSI M44-S3 for Susceptibility Test Interpretive Criteria

The hyperlinks included for certain antifungal drugs in the table below lead to information concerning:

  • Exceptions to the recognized standard of CLSI M27-S4 and CLSI M44-S3
  • Additional STIC recognized in part from standard CLSI M27-S3
  • Additional FDA-identified STIC for certain drug-yeast combinations not included in a recognized standard

Drug

Route of
Administration

STIC for Drug
Included in CLSI
M27-S4 or CLSI
M44-S3
Standards

Exceptions or
Additions to CLSI
M27-S4 and CLSI
M44-S3 Standards

Last Updated

Amphotericin B*InjectionNoNo12/13/17
AnidulafunginInjectionYesNo12/13/17
CaspofunginInjectionYesYes12/13/17
FluconazoleInjection, OralYesYes12/13/17
FlucytosineOralNoYes12/13/17
Griseofulvin*OralNoNo12/13/17
Isavuconazole*Injection, OralNoNo12/13/17
ItraconazoleInjection, OralNoYes12/13/17
Ketoconazole*OralNoNo12/13/17
MicafunginInjectionYesYes12/13/17
Nystatin*OralNoNo12/13/17
Posaconazole*Injection, OralNoNo12/13/17
Terbinafine*OralNoNo12/13/17
VoriconazoleInjection, oralYesYes12/13/17

*No susceptibility test interpretive criteria are recognized by FDA for this drug at this time.

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