Applied Antibiotic Use & Antimicrobial Stewardship

Vocabulary practice cards covering common veterinary antibiotics, empirical therapy, storage requirements, and antimicrobial stewardship principles based on lecture notes.

Empirical Therapy

Therapy based on experience; a clinically-educated guess frequently justified when there is no access to microbiology or therapy is needed immediately.

Four Quadrant Therapy (Equine)

A combination typically consisting of an aminoglycoside and a (potentiated) beta-lactam, commonly referred to as "PenGent."

Four Quadrant Therapy (Small Animal)

A combination typically consisting of a fluoroquinolone and a (potentiated) beta-lactam, commonly referred to as "Baytril n' Clav."

Tilmicosin (Production Animal Precautions)

Indicated only for non-dairy cattle and must never be administered $IV$.

Oxytetracycline (IM Side Effects)

Oily preparations are irritating and can cause sterile abscessation following $IM$ injection; use caution if near to slaughter.

Beta-Lactam Administration Rule

These should be kept refrigerated, and as a rule, "nothing white goes into a vein."

Fluoroquinolones (Australian Regulation)

Subject to a nationwide ban in all Australian food-producing species, including cattle.

Aminoglycoside Injectables (Australian Regulation)

Prohibited in food-producing species, as the APVMA has flagged deregistration for products where systemic absorption occurs.

Metronidazole

Commonly used in veterinary medicine for pets and horses but should not be used in production animals.

Limitations of In Vitro Susceptibility Testing

It is a predictor of in vivo success and should guide rather than dictate therapy, as it uses monomorphic populations growing logarithmically under specific laboratory conditions.

Biofilms

Protective layers produced by bacteria like Staph. aureus and Pseudomonas aeruginosa that many antibiotics cannot penetrate, though fluoroquinolones can.

Antibiotic Storage (Light Protection)

Drugs in brown bottles must be protected from light and should not be aliquoted into clear syringes for owners.

Antibiotic Storage (Moisture Protection)

Drugs individually wrapped in foil must be protected from moisture and sometimes light.

Antibiotic Resistance Origin

Arises from spontaneous mutations in bacterial DNA; antibiotics do not cause resistance but select for it, leading to proliferation.

MRSA

Methicillin-resistant Staphylococcus aureus.

ESBL

Extended-spectrum beta-lactamase.

CRE / CPE

Carbapenem-resistant Enterobacterales / Carbapenemase-producing Enterobacterales.

ASTAG High Rating Antibiotics

Antibacterial classes of high importance to human health, including 3rd generation cephalosporins, fluoroquinolones, carbapenems, and glycopeptides.

ASTAG Low Rating Antibiotics

Antibacterial classes including narrow spectrum penicillins (e.g., Procaine Penicillin G), tetracyclines, and macrolides.

Clinical Endpoint

A defined time to stop therapy, such as 24 hours after a patient starts eating or drinking voluntarily, to minimize the course duration.

Antimicrobial Stewardship "Get in, hit hard, get out"

A strategy involving not delaying treatment, giving appropriate high doses (dose-dependent) or frequency (time-dependent), and minimizing course duration.