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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

Performance Methods and Quality Control

FDA recognizes consensus standards for performance standards, methods standards, and quality control parameter standards including ranges for antimicrobial susceptibility testing.

Susceptibility Test Interpretive Criteria

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 published in:

  • Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antifungal Susceptibility Testing of Yeasts. 3rd Ed. CLSI document M27M44S; 2022. (CLSI M27M44S)

If the table indicates that STIC for a drug are included in M27M44S and there are no additions or exceptions, CLSI M27M44S contains all of the STIC recognized by FDA for that drug.

If one of these standards 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.

Susceptibility Test Interpretive Criteria Recognized or Otherwise Identified by FDA

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

  • Exceptions to the recognized standard of CLSI M27M44S
  • Additional FDA-identified STIC for certain drug-yeast combinations not included in a recognized standard

Downloadable File (XLS-16KB)


Route of

STIC for Drug
Included in CLSI
M27M44S Standards

Exceptions or
Additions to CLSI
M27M44S Standards

Amphotericin B* Injection No No
Anidulafungin Injection Yes No
Caspofungin Injection Yes No
Fluconazole Injection, Oral Yes No
Flucytosine* Oral No No
Griseofulvin* Oral No No
Isavuconazole* Injection, Oral No No
Itraconazole Oral No Yes
Ketoconazole* Oral No No
Micafungin Injection Yes No
Nystatin* Oral No No
Posaconazole* Injection, Oral No No
Rezafungin Injection Yes Yes
Terbinafine* Oral No No
Voriconazole Injection, oral Yes No

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

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