Herd Health/Antibiotics Flashcards
What are the main considerations for using Antibiotics?
Cidal or Static? Time or concentration dependent? Intracellular, extracellular, or both? Spectrum of activity Water or lipid soluble? Restrictions? PK/PD approach = time above MIC and AUC/MIC
What is the rule about Sulfonamides?
Sulfadimethoxine is the only antibiotic that can be used on dairy cattle
Are non-potentiated sulfas bacteriocidal or static?
Bacteriostatic
Are potentiated sulfas bacteriocidal or static?
Bacteriocidal
Sulfonamides
Time dependent
Used for mild respiratory disease and diarrhea or foot rot
Best use: Coccidiosis and the secondary invaders
Broad spectrum G+, G- and some protozoa
Action: mimick PABA precursor at the beginning of the THFA pathway blocking production of the active form of folic acid
Beta Lactams
Time dependent
Bacteriocidal
Action: Bind to Penicillin Binding Protein
G- require more exposure than G+
Poor intracellular activity
Do not penetrate well into the CNS. Prostate or Uterus
What drugs should you not use together?
Beta Lactam and a bacteriostatic drug
What is the spectrum for Natural Penicillins?
G+
Anaerobes
select G- (Listeria) and spirochetes
What is the spectrum for Aminopenicillins?
more G-
some strains of E. coli and Salmonella
Cephalosporins
More g- as generation increases
Tetracycline
AUC/MIC dependent Broad spectrum and Bacteriostatic Action: Binds to the 30s ribosome Poor oral absorption Lipophilic Accumulates intracellularly eliminated in the feces
Aminoglycosides
Bacteriocidal Concentration dependent Aerobic G- Highly water soluble poor lipid soluble Oral absorption is poor Action: irreversibly binds to the 30s ribosome Accumulate in lysosomes and mitochondria Nephrotoxic and ototoxic
Florfenicol
Bacteriostatic Time dependent Broad spectrum G-, some G+ Action: inhibits protein synthesis, blocks 50s ribosome Lipid soluble Concentrates in tear film Achieves concentration in CNS Good penetration into diseased lung Binding site near macrolides = competition
Macrolides
intracellular activity fairly broad spectrum - G- and G+ Action: inhibits protein synthesis by binding to 50s ribosome Time dependent Bacteriostatic Concentrate in cells that are more acidic than plasma Good absorption through the gut Tissue concentration higher than serum
Lincosamides
USED IN SWINE ONLY!
inhibit protein synthesis by binding to the 50s ribosome
What does Lincosamides treat?
Mycoplasma pneumonias
Bacterial arthritis
Fluoroquinolones
HIGHLY RESTRICTED! Bacteriocidal Concentration dependent Most G- bacteria, G+ Action: Inhibit bacterial DNA replication and transcription by binding the A subunit of DNA gyrase Wide distribution Lipid soluble Treats Campylobacter and Salmonella
Lactating Cow
a cow that is older than 20 months of age whether she has a calf or not
Non Lactating Cow
A cow less than 20 months of age whether she is making milk or not
Dry Cow
A lactating cow that is pulled off the milk strain and is over 20 months of age
Who approves prescription and OTC drugs?
FDA
Who approves chemical used as pesticides?
EPA
What is the rule for EPA products?
cannot be used extra-label
ELDU
Extra Label Drug Use
AMDUCA
Animal Medical Drug Use Clarification Act
ELDU is not Allowed:
for EPA approved products with anti-infectives added to feed for production reasons with fluoroquinolones with sulfonamides Products labeled for production purposes with cephalosporins For cost or convenience Products not FDA approved For non-medical use of sedatives not labeled for food animals
NADA number
veterinary made purpose drug approved by the FDA
ANADA number
human drug that can be used for humans or by vets and FDA approved
MRL - Maximum Residue Level
Highest level of residues they will allow in another country besides the US
First Tier of Residue Testing
evaluating samples per chemical compound class for each of the production classes chosen to be tested in tier 1
Second Tier of Residue Testing
Focuses on samples taken at the establishment level for KIS testing
Third Tier of Residue testing
Designed to target herds and flocks or origin
What are the drugs prohibited by the ELDU?
Chloramphenicol Clenbuterol Diethylstillbesterol Dimetridazole Ipronidazole Nitroimidazole Furazolidone Fluoroquinolones Glycopeptides Phenylbutazone
FARAD
Food Animal Residue Avoidance Databank
What is a Type A Article Veterinary Feed Directive?
Raw Product
What is a Type B feed?
product that is made more concentrated and must be mixed with another medicated feed. Cannot be fed straight!
What is Type C feed?
medicated feed fed as is and unadulterated
Who enforces the Veterinary Feed Directive?
FDA
What are the terms of use for a Veterinary Feed Directive?
Must document a need Must have a VCPR Drug must be approved for species and production class Dose, Duration, Route, and Indication ELDU and MUMS not allowed
