Drugs

Antibacterial Susceptibility Test Interpretive Criteria

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

The safety and efficacy of these drugs in treating clinical infections due to such bacteria may or 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 antibacterial 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 standard published in:

  • Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing. 28th ed. CLSI supplement M100. Wayne, PA: Clinical and Laboratory Standards Institute; 2018. (CLSI M100disclaimer icon)

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/bacteria combinations, FDA recognizes in part the standards published in:

  • Clinical and Laboratory Standards Institute (CLSI). Methods for Antimicrobial Dilution and Disk Susceptibility Testing of Infrequently Isolated or Fastidious Bacteria. 3rd ed. CLSI guideline M45. Wayne, PA: Clinical and Laboratory Standards Institute; 2015.
  • Clinical and Laboratory Standards Institute (CLSI). Susceptibility Testing of Mycobacteria, Nocardiae, and Other Aerobic Actinomycetes; Approved Standard. 2nd ed. CLSI guideline M24-A2. Wayne, PA: Clinical and Laboratory Standards Institute; 2011.
  • Clinical and Laboratory Standards Institute (CLSI). Methods for Antimicrobial Susceptibility Testing for Human Mycoplasmas; Approved Guideline. CLSI guideline M43-A. Wayne, PA: Clinical and Laboratory Standards Institute; 2011.

If one of these three 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.

FDA recognition of STIC standard(s) for a drug does include recognition of surrogate testing methods for that drug.

Susceptibility Test Interpretive Criteria Recognized or Otherwise Identified by FDA

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

  • Recognitions, Exceptions, or Additions to the recognized standard of CLSI M100
  • Additional STIC recognized in part from standards CLSI M45, M24-A2, and M43-A
  • Additional FDA-identified STIC for certain drug-bacteria combinations not included in a recognized standard

Downloadable File (XLS-16KB)

Drug

Route of
Administration

STIC for Drug
Included in
CLSI M100
Standard

Exceptions or
Additions to
CLSI M100
Standard

Last Updated

AmikacinInjectionYesYes12/13/17
AmoxicillinOralYesNo12/13/17
Amoxicillin
and clavulanate
OralYesYes12/13/17
AmpicillinInjection, OralYesNo12/13/17
Ampicillin and
sulbactam
InjectionYesYes12/13/17
AzithromycinInjection, OralYesYes12/13/17
AztreonamInjectionYesYes12/13/17
Bacitracin*InjectionNoNo12/13/17
Bedaquiline*OralNoNo12/13/17
Bismuth subcitrate potassium, Metronidazole, and Tetracycline hydrochloride*OralNoNo02/09/18
Capreomycin*InjectionNoNo12/13/17
CefaclorOralYesYes12/13/17
CefadroxilOralNoYes12/13/17
CefazolinInjectionYesYes12/13/17
CefdinirOralYesYes12/13/17
Cefditoren pivoxilOralYesYes12/13/17
CefepimeInjectionYesYes12/13/17
CefiximeOralYesNo12/13/17
CefoperazoneInjectionYesYes12/13/17
CefotaximeInjectionYesYes12/13/17
CefotetanInjectionYesYes12/13/17
CefoxitinInjectionYesYes12/13/17
Cefpodoxime
proxetil
OralYesNo12/13/17
CefprozilOralYesYes12/13/17
Ceftaroline fosamilInjectionYesNo12/13/17
CeftazidimeInjectionYesYes12/13/17
Ceftazidime and
avibactam
InjectionYesNo06/26/18
CeftibutenOralYesYes12/13/17
Ceftolozane and
tazobactam
InjectionYesYes06/26/18
CeftriaxoneInjectionYesYes12/13/17
Cefuroxime axetilOralYesYes12/13/17
CefuroximeInjectionYesYes12/13/17
CephalexinOralYesNo12/13/17
ChloramphenicolInjectionYesYes12/13/17
CiprofloxacinOral, InjectionYesYes12/13/17
ClarithromycinOralYesYes02/09/18
ClindamycinInjection, OralYesNo12/13/17
Clofazimine*OralNoNo12/13/17
ColistimethateInjectionYesYes12/13/17
DalbavancinInjectionYesNo06/26/18
Dapsone*OralNoNo12/13/17
DaptomycinInjectionYesNo12/13/17
DelafloxacinInjectionNoYes12/13/17
DemeclocyclineOralNoYes12/13/17
DicloxacillinOralYesNo12/13/17
DoripenemInjectionYesYes12/13/17
DoxycyclineOral, InjectionYesYes12/13/17
EravacyclineInjectionNoYes8/28/2018
ErtapenemInjectionYesYes12/13/17
ErythromycinOral, InjectionYesNo12/13/17
Erythromycin
ethylsuccinate and
sulfasoxazole
acetyl*
OralNoNo12/13/17
Ethambutol*OralNoNo12/13/17
Ethionamide*OralNoNo12/13/17
Fidaxomicin*OralNoNo12/13/17
Fosfomycin
tromethamine
OralYesNo12/13/17
GemifloxacinOralYesNo12/13/17
GentamicinInjectionYesYes12/13/17
Imipenem and
cilastatin
InjectionYesYes12/13/17
Isoniazid*OralNoNo12/13/17
Isoniazid, Pyrazinamide, and Rifampin*OralNoNo02/09/18
KanamycinInjectionYesYes12/13/17
Lansoprazole, Amoxicillin, and Clarithromycin*OralNoNo02/09/18
LevofloxacinOral, InjectionYesYes12/13/17
Lincomycin*InjectionNoNo12/13/17
LinezolidInjection, OralYesNo12/13/17
LoracarbefOralYesYes12/13/17
MeropenemInjectionYesYes12/13/17
Meropenem and
vaborbactam
InjectionNoYes12/13/17
Methenamine
Hippurate*
OralNoNo12/13/17
MetronidazoleInjection, OralYesNo12/13/17
MinocyclineOral, InjectionYesYes12/13/17
MoxifloxacinOral, InjectionYesYes12/13/17
Nafcillin*InjectionNoNo12/13/17
Neomycin sulfate*OralNoNo12/13/17
NitrofurantoinOralYesNo12/13/17
OfloxacinOralYesYes12/13/17
OmadacyclineInjection, OralNoYes10/02/18
Oritavancin
diphosphate
InjectionYesNo12/13/17
OxacillinInjectionYesNo12/13/17
PenicillinInjectionYesNo12/13/17
Penicillin VOralYesNo12/13/17
Piperacillin and
tazobactam
InjectionYesYes06/26/18
PlazomicinInjectionNoYes06/26/18
Polymyxin B
Sulfate
InjectionYesYes12/13/17
Pyrazinamide*OralNoNo12/13/17
Quinupristin and
dalfopristin
InjectionYesYes12/13/17
Rifabutin*OralNoNo4/26/18
RifampinOral, InjectionYesYes12/13/17
Rifapentine*OralNoNo02/09/18
Rifaximin*OralNoNo02/09/18
SpectinomycinInjectionYesNo12/13/17
StreptomycinInjectionYesYes12/13/17
TedizolidOral, InjectionYesYes06/26/18
TelavancinInjectionYesNo12/13/17
TelithromycinOralYesYes12/13/17
TetracyclineOralYesYes12/13/17
Ticarcillin and
clavulanate
InjectionYesYes12/13/17
TigecyclineInjectionNoYes12/13/17
TobramycinInjectionYesYes12/13/17
Trimethoprim
hydrochloride
OralYesNo12/13/17
Trimethoprim and
sulfamethoxazole
Oral, InjectionYesYes12/13/17
VancomycinInjectionYesYes12/13/17
Vancomycin*OralNoNo12/13/17

*No STIC are recognized by FDA for this drug at this time.

Page Last Updated: 10/05/2018
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