Chapter 1. Design and Methods

Antimicrobial Classification

Categorization of Antimicrobials

Categories of antimicrobials used in this report were taken from the document Categorization of Antimicrobial Drugs Based on Importance in Human MedicineFootnote 66 by Health Canada's Veterinary Drugs Directorate (Table 6). Antimicrobials are considered to be of Very High Importance in Human Medicine (Category I) when they are essential for the treatment of serious bacterial infections and there is no or limited availability of alternative antimicrobials for effective treatment. These antimicrobials include amoxicillin-clavulanic acid, ceftiofurFootnote 67, ceftriaxone, ciprofloxacin, and telithromycin. Antimicrobials of High Importance in Human Medicine (Category II) consist of those that can be used to treat a variety of infections, including serious infections, and for which alternatives are generally available. Bacteria resistant to antimicrobials of this category are generally susceptible to Category I antimicrobials, which could be used as alternatives. Antimicrobials of Medium Importance in Human Medicine (Category III) are used in the treatment of bacterial infections for which alternatives are generally available. Infections caused by bacteria resistant to these antimicrobials can, in general, be treated with Category II or I antimicrobials. Antimicrobials of Low Importance in Human Medicine (Category IV) are currently not used in human medicine.

Table 6. Categorization of antimicrobial drugs based on importance in human medicine

Category of importance in human medicine Antimicrobial class
I Very High Importance Carbapenems
Cephalosporins – the third and fouth-generations
Nitroimidazoles (metronidazole)
Penicillin-β-lactamase inhibitor combinations
Polymyxins (colistin)
Therapeutic agents for tuberculosis (e.g. ethambutol, isoniazid, pyrazinamide, and rifampin)
II High Importance Aminoglycosides (except topical agents)
Cephalosporins – the first and second-generations (including cephamycins)
Fusidic acid
Quinolones (except fluoroquinolones)
III Medium Importance Aminocyclitols
Aminoglycosides (topical agents)
IV Low Importance Flavophospholipols

Table 7. List of antimicrobials from the Farm Swine questionnaire database for each ATCvetFootnote 68 class

ATCvet Class Antimicrobial
I Third-generation cephalosporins (QJ01DD) Ceftiofur (QJ01DD90)
Fluoroquinolones Enrofloxacin (QJ01MA90)
II Amphenicols (QJ01BA) Florfenicol (QJ01BA90)
Penicillins with extended spectrum (QJ01CA) Ampicillin (QJ01CA01)
Amoxicillin (QJ01CA04)
ß-Lactamse sensitive penicilliins (QJ01CE) Penicillin (QJ01CE01)
Combination of sulfadoxine and trimethoprim (QJ01EW) Trimethoprim-sulfadoxine (QJ01EW13)
Macrolides (QJ01FA) Erythromycin (QJ01FA01)
Tylosin (QJ01FA90)
Tilmicosin (QJ01FA91)
Tulathromycin (QJ01FA94)
Lincosamides (QJ01FF) Lincomycin (QJ01FF02)
Streptogramins (QJ01FG) Virginiamycin (QJ01FG90)
Other aminoglycosides (QJ01GB) Neomycin (QJ01GB05)
Combinations of antibacterials (QJ01RA) Penicillin-streptomycin (QJ01RA01)
Chlortetracycline-sulfamethazine-penicillin (QJ01RA90)
Oxytetracycline-neomycin (QJ01RA90)
Tetracycline-neomycin (QJ01RA90)
Lincomycin-spectinomycin (QJ01RA94)
Other antibacterials (QJ01XX) Spectinomycin (QJ01XX04)
III Tetracyclines (QJ01AA) Chlortetracycline (QJ01AA03)
Oxytetracycline (QJ01AA06)
Tetracycline (QJ01AA07)
Chlortetracycline, combinations (QJ01AA53)
Sulfonamides (QJ01EQ) Combinations of sulfonamides (QJ01EQ30)
Pleuromutilins (QJ01XQ) Tiamulin (QJ01XQ01)
Other antibacterials (QJ01XX) Bacitracin (QJO1XX10)
IV No ATCvet code Bambermycin (No ATCvet code)
Pyranes and hydropyranes (QP51AH) Salinomycin (QP51AH01)

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: