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  1. Development Resources

Notice of Updates

Sign up to receive FDA Recognized Antimicrobial STIC Breakpoints email notifications Little-Envelope

For information regarding prior changes to the STIC webpages, see https://www.govinfo.gov/content/pkg/FR-2019-05-03/pdf/2019-09007.pdf

https://www.federalregister.gov/documents/2020/10/22/2020-23439/21st-century-cures-act-annual-compilation-of-notices-of-updates-from-the-susceptibility-test

https://www.federalregister.gov/documents/2023/05/18/2023-10603/21st-century-cures-act-annual-compilation-of-notices-of-updates-from-the-susceptibility-test

https://www.federalregister.gov/documents/2024/04/09/2024-07495/21st-century-cures-act-annual-compilation-of-notices-of-updates-from-the-susceptibility-test

Updates to Standards Recognition

As of May 28, 2024 the following standards are no longer recognized:

Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing. 33rd ed. CLSI supplement M100. Wayne, PA: Clinical and Laboratory Standards Institute; 2023.

As of May 28, 2024 with certain exceptions, FDA recognizes the standard published in:

Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing. 34th ed. CLSI supplement M100. Clinical and Laboratory Standards Institute; 2024.

Updates by Drug:

Drug

Route of Administration

Action Taken

Therapeutic Category

Date

Amikacin

Injection

FDA does not recognize M100 standard (MIC and disk diffusion) for Enterobacterales and Pseudomonas aeruginosa

Antibacterial

4/21/2023

Amoxicillin and clavulanate

Oral

FDA does not recognize M100 standard and provides STIC for Haemophilus influenzae.

Antibacterial

5/17/2022

Azithromycin

Oral, Injection

For Neisseria gonorrhoeae, FDA has reviewed STIC and concludes no changes are needed at this time. Rationale

Antibacterial

10/14/2021

Cefadroxil

Oral

FDA removed the statement “Susceptibility of Enterobacteriaceae to cefadroxil may be deduced from testing cefazolin.” Rationale

Antibacterial

4/27/2022

Cefazolin

Injection

FDA does not recognize M100 standard for cefazolin as a surrogate to predict susceptibility of oral cephalosporins when used for the treatment of uncomplicated UTI caused by Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. Rationale

Antibacterial

10/20/2022

Cefazolin

Injection

For Enterobacterales, FDA has reviewed STIC and the updated standard is recognized. Rationale

Antibacterial

10/14/2021

Cefepime

Injection

FDA recognizes M100 susceptible-dose dependent standard (MIC and disk diffusion) for Enterobacterales

Antibacterial

6/21/2023

Cefepime and Enmetazobactam

Injection

FDA identified STIC (MIC and disk diffusion) for Enterobacterales and P. aeruginosa.

Antibacterial

2/22/2024

Cefiderocol

Injection

FDA recognizes M100 MIC standard and identifies disk diffusion STIC for S. maltophilia. Rationale

Antibacterial

11/12/2024

Cefiderocol

Injection

FDA recognizes M100 (disk diffusion) standards for Enterobacterales.

Antibacterial

1/31/2023

Cefiderocol

Injection

FDA recognizes M100 MIC standard for Enterobacteriaceae.

Antibacterial

10/14/2021

Cefiderocol

Injection

FDA has updated STIC and added STIC for Acinetobacter baumannii complex.

Antibacterial

9/25/2020

Cefoxitin

Injection

FDA recognizes M100 standard for Staphylococcus aureus complex and Staphylococcus lugdunensis; FDA recognizes M100 disk diffusion standard for Staphylococcus epidermidis and other Staphylococci spp.

Antibacterial

10/04/2022

Ceftaroline fosamil

Injection

FDA recognizes the M100 standard (MIC and disk diffusion) for Staphylococcus aureus. Rationale

Antibacterial

6/25/2024

Ceftaroline fosamil

Injection

For Staphylococcus aureus, FDA has reviewed the STIC and concludes no changes are needed at this time. Rationale

Antibacterial

4/16/2020

Ceftazidime

Injection

FDA concurs with CLSI to remove STIC (MIC) for S. maltophilia. Rationale

Antibacterial

5/15/2024

Ceftobiprole medocaril sodium

Injection

FDA identified STIC for S. aureus, S. pyogenes, and Enterobacterales (MIC and disk diffusion), and for S. pneumoniae, H. influenzae and H. parainfluenzae (MIC).

Antibacterial

4/03/2024

Ceftolozane Tazobactam

Injection

FDA recognizes M100 standard for Haemophilus influenzae.

Antibacterial

10/14/2021

Ceftolozane and tazobactam

Injection

FDA recognizes M100 disk diffusion standard for Enterobacterales.

Antibacterial

5/17/2022

Ciprofloxacin

Oral, Injection

For Salmonella spp., the updated standard is recognized.

Antibacterial

2/28/2020

Colistimethate

Injection

FDA does not recognize M100 standard (MIC) for Enterobacterales, Pseudomonas aeruginosa, or Acinetobacter spp. Rationale

Antibacterial

1/17/2023

Daptomycin

Injection

FDA recognizes M100 standard (MIC) for E. faecium and Enterococcus spp. other than E. faecium. Rationale

Antibacterial

8/2/2024

Daptomycin

Injection

FDA updated STIC. Rationale

Antibacterial

8/25/2020

Delafloxacin

Injection, Oral

FDA identified STIC for Staphylococcus lugdunensis for Acute Bacterial Skin and Skin Structure Infections.

Antibacterial

10/06/2020

Fluconazole

Injection, Oral

FDA recognizes M27M44S susceptible-dose dependent standard (MIC and disk diffusion) for Candida species.

Antifungal

8/10/2023

Gentamicin

Injection

FDA does not recognize M100 standard (MIC and disk diffusion) for Enterobacterales and Pseudomonas aeruginosa

Antibacterial

4/21/2023

Imipenem-Cilastatin-Relebactam

Injection

FDA recognizes M100 standard for Enterobacteriaceae, Pseudomonas aeruginosa, and anaerobes.

Antibacterial

10/14/2021

Imipenem-Cilastatin-Relebactam

Injection

FDA identified STIC for Acinetobacter calcoaceticus-baumannii complex and Haemophilus influenzae.

Antibacterial

6/4/2020

Lefamulin

Oral, Injection

FDA recognizes M100 standard (MIC and disk diffusion) for Staphylococcus aureus (methicillin-susceptible isolates), Streptococcus pneumoniae, and Haemophilus influenzae.

Antibacterial

2/16/2023

Lefamulin

Oral, Injection

FDA does not recognize M100 disk diffusion standard and provides STIC for Streptococcus pneumoniae and Haemophilus influenzae.

Antibacterial

5/17/2022

Lefamulin

Oral, Injection

FDA recognizes M100 standard for Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae.

Antibacterial

10/14/2021

Levofloxacin

Oral, Injection

For Salmonella spp., the updated standard is recognized.

Antibacterial

2/28/2020

Linezolid

Oral, Injection

FDA recognizes M100 (disk diffusion) standard for S. aureus.

Antibacterial

5/28/2024

Ofloxacin

Oral

For Salmonella spp., the updated standard is recognized.

Antibacterial

2/28/2020

Omadacycline

Injection, Oral

FDA updated disk breakpoints for Streptococcus pneumoniae for community acquired bacterial pneumonia.

Antibacterial

8/25/2020

Oxacillin

Injection

FDA concurs with the revised CLSI STIC for Staphylococcus by species level. Rationale;
FDA references Cefoxitin STIC for Staphylococcus spp. as a surrogate test.

Antibacterial

10/04/2022

Piperacillin and Tazobactam

Injection

FDA has updated STIC (MIC and disk diffusion) for P. aeruginosa. FDA identified a susceptible-dose dependent breakpoint. FDA does not recognize M100 standard for a susceptible, intermediate, and resistance breakpoints. Rationale

Antibacterial

3/22/2024

Piperacillin and Tazobactam

Injection

FDA has updated STIC (MIC and disk diffusion) for Enterobacterales. FDA has recognized M100 standard for susceptible and resistant breakpoints and updated an intermediate breakpoint. FDA does not recognize M100 standard for a susceptible dose dependent breakpoint. Rationale

Antibacterial

1/17/2023

Pivmecillinam

Oral

FDA recognizes M100 standard (MIC and disk diffusion) for Enterobacterales

Antibacterial

4/24/2024

Plazomicin

Injection

FDA recognizes M100 standard (MIC and disk diffusion) for Enterobacterales

Antibacterial

4/21/2023

Polymyxin B

Injection

FDA does not recognize M100 standard (MIC) for Enterobacterales, Pseudomonas aeruginosa, or Acinetobacter spp. Rationale

Antibacterial

1/17/2023

Rezafungin

Injection

FDA identified STIC (MIC and disk diffusion) for C. albicans, C. glabrata, and C. tropicalis.

FDA has reviewed STIC (MIC) for C. parapsilosis, and the M27M44S standard is recognized.

FDA identified STIC (disk diffusion) for C. parapsilosis.

Antifungal

4/18/2023

Sulbactam and Durlobactam

Injection

FDA recognizes M100 standard (MIC and disk diffusion) for Acinetobacter baumannii-calcoaceticus complex.

Antibacterial

6/06/2023

Sulopenem etzadroxil and probenecid

Oral

FDA identified STIC (MIC and disk diffusion) for Enterobacterales.

Antibacterial

10/25/2024

Tedizolid phosphate

Oral, injection

FDA recognizes M100 (disk diffusion) standard for S. aureus, Streptococcus spp. beta-hemolytic group, and Streptococcus spp. viridans group.

Antibacterial

5/28/2024

Telithromycin

Oral

FDA has removed telithromycin STIC as the drug is no longer approved in any application under section 505 of the FD&C Act (see 84 FR 47309).

Antibacterial

10/14/2021

Tobramycin

Injection

FDA does not recognize M100 standard (MIC and disk diffusion) for Enterobacterales and Pseudomonas aeruginosa

Antibacterial

4/21/2023

* M100 standard in the table refers to CLSI Performance Standards for Antimicrobial Susceptibility Testing, 34th ed. CLSI supplement M100; 2024.

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