Large Animal Pharmacology Flashcards
Tolerance
legal amount at time of meat/milk going to market
Target Test Level
*MILK ONLY
-used for antibiotics that have been used in the past prior to these regulations being put into place
-acceptable by FDA-so a certain amount of residue within a range (ex. penicillin residue will not cause prosecution until 5 ppb)
doesn’t protect milk producers from court enforcement/right to do something at a later date
Withdrawal Time
amount of time for a drug to go below a target level in a target tissue
What factors affect withdrawal times? (4)
PK/PD (pharmacokinetics/dynamics) route frequency dosage **if you change any of these it can alter withdrawal time=extra label use
What are the critically important antimicrobial drugs? (4)
3rd generation cephalosporins (ceftiofur)
fluoroquinolones
macrolides
trimeth/sulfa
What are the highly important antimicrobial drugs?
penicillin’s
tetracycline’s
phenicols
What are the major food animal species? (4)
cattle
pig
chickens
turkey
What are the major non-food animal species? (3)
dogs
cats
horses
What are the minor food animal species? (5)
goats sheep alpacas catfish honeybees
Residue
any substance that is foreign to the body
ex.) drug, pesticide ect
Violative Residue
drug residue found to be above the regulatory limit (tolerance or target level) in tissue, milk or eggs (FDA regulates)
What ways can you give a drug according to AMDUCA?
- parenterally (IV/IM-or anything outside the instestines)
- topical
- intramammary
- in water
What is a VFD drug?
essentially a script to use “medically important” antimicrobials in animal feed
check with FARAD for approved drug combinations
- vfd= vet feed directive aka antibiotics added to feed
What is required for a VFD to be valid? (i.e what has to be on a VFD label) (6)
- must be from a veterinarian who has a valid VCPR for the operation
- one vet (not a clinic)
- one client
- one feed distributor
- one or more animal production sites (can have more than one under same feed mill/managed the same)
- one medication (+/- legal combos)
Are water soluble medications affected by VFD requirements?
NO, water soluble are prescription only
When does AMDUCA allow veterinarians to prescribe drugs outside approved label directions? (ON TEST) (4)
when:
- it is clinically effective
- has the needed ingredient
- is in the proper dosage form
- is labeled for the indication/disease
What are some label requirements for veterinarians writing ELDU to clients?
- name and contact info of vet
- established name of drug
- any specific directions (species, id of flock/herd, dosage freq, route, duration)—–>don’t just say “use as directed”
- cautionary statements
- for food producing species: withdrawal times/withholding, discard times for meat milk eggs/other
What are some record requirements that the producer must have?
*shouldn’t be in something that can be altered (google spreadsheet/word doc)
- ID the animals
- species
- # of animals treated
- medical condition
- established name of drug and active ingredient
- dosage prescribed or used
- route
- duration of tx
- withdrawal/witholding times
How long should records be kept after an animal has been treated?
2 years
What are some reasons a drug may be prohibited?
- cancer
- toxicities in humans
- bacterial resistance
What are the drugs that are prohibited for ANY use in food animals? (ON TEST) (6)
- Chloramphenicol
- Diethylstilbestrol (DES)
- Clenbuterol
- Nitroimidazole–> dimetridazole, ipronidazole, metronidazole
- Nitrofurans–> furazolidine, nitrofurazone
- Glycopeptides–> vancomyacin
Which fluoroquinolones are prohibited from ELDU?
- Enrofloxacin-Baytril is for respiratory diseases ONLY (cattle), and respiratory and colibacilosisi in swine
- Baytril CA-1- conditional approval for anaplasmosis
- NOT for female dair cattle >20 months
Which drug is prohibited from ELDU in dairy cattle >20 months or older?
Phenylbutazone
What are the exception to the ELDU of sulfonamides?
can use sulfadimethxine, sulfabromethazine and silfaethoxipyriazine
-approved for pneumonia and foot rot
What are the three ways that ELDU can be used for?
prevention
Control
Treatment
What is prevention?
no animals currently showing signs but infection is likely based off of animals history
What is treatment?
animals showing current clinical signs
What is control?
animals are sub-acute or animals showing signs in larger group
What are some ELDU restrictions for cephalosporins?
- cant be used at unapproved doses, freq, durations, or routes
- cant be used if not approved for that species (major classes only)
- cannot be used for prevention!
can change the indication
When can cephalosporin’s be used? (aka when is ELDU ok?)
- ELDU for cephapirin products in food-producing animals (IMM only in USA)
- used to treat or control extra label disease indication
- extra label in minor species (duck/rabbits)
What is the MUMS act of 2004?
minor use and minor species health act
- can make more medications legally available to vets and owners for treating minor species and uncommon diseases
- allows companies to bring new drugs to market under conditional approval
- ELDU in feed lower priority–>does NOT allow drug residues
Which drugs have special restrictions for Grade A dairy operations?
- non-medical grade DMSO
- Dipyrone
- Colloidal silver
- *monitored by PMO (Pasteurize Milk Ordinance)
Which antimicrobials are included under the Beta Lactams?
Penicillin’s
Cephalosporin’s
Monobactams
Carbapenems
**PCMC–>Penis’s Can Make you Cum
What is the benefit of adding an amino group to the penicillin G structure?
Aminopenicillins
increased spectrum of activity to include more gram -
What is the affect of adding a hydroxyl group to the amoxicillin structure?
increased acid stability (improved oral absoprtion)
What can penicillin’s be used to treat in cattle?
- BRD (bovine respiratory disease)
- mastitis
- metritis
- foot rot
____A____ and _____B____ are two naturally occurring antibiotics from fungi that primarily affect ___C__ __D____ organisms. (fill in the blank)
A. Penicillin G
B. Penicillin V
C. Gram
D. Positive
Penicillin G has a poor oral bioavailability. (T/F)
True
What are the routes of administration for Penicillin G?
IV, IM
What is the spectrum of activity for Penicillin G/V?
Gram + aerobes/anaerobes, Gram - anaerobes
What is the spectrum of activity for Ampicillin?
Gram + aerobes, some gram - aerobes
G +and G- anaerobes
What drug class is Ampicillin?
B-lactam
Aminopenicillin
Ampicillin is NOT lactamase sensitive due to its amino group structure. (T/F)
F- is lactamase sensitive
What are the routes of administration for Ampicillin?
IM, IV, SQ
poor oral bioavailability
What is the spectrum of activity of Amoxicillin?
G + aerobes some G - aerobes
G + and G - anaerobes
What are the routes of administration for amoxicillin?
PO
Is Amoxicillin lactamase resistant?
NO it is lactamase sensitive (aminopenicillin)
What is the drug class of Cloxacillin?
beta lactamase
lactamase resistant penicillin
What is the spectrum of activity of Cloxacillin?
- narrow
- primarily G + cocci (anti-staph penicillin)
What are the route of administration on Cloxacillin?
- Intramammary
- prolonged activity due to extended release in mammary gland
What are the adverse effects of beta lactams (specifically penicillin’s)?
hypersensitivity reactions
What is the drug class of Cephapirin?
beta lactam
Cephalosporin
1st generation
What is the spectrum of activity of Cephaparin?
G+ aerobes (esp staph and strep)
some G- aerobes
unpredictable anaerobic activity
What are the routes of administration of Cephapirin?
intramammary
Is Cephapirin resistant to lactamase?
resistant to some, not active in MRS
What is the drug class of Ceftiofur?
beta lactam
Cephalosporin
3rd generation
What is the spectrum of activity for Ceftriofur?
G- and G+ aerobes (more G- than 1st gen)
G+ and G- anaerobes
What is the route of administration for Ceftiofur?
SC, IM, Intramammary
Is Ceftiofur resistant to lactamase?
more resistant than 1st gen, not active in MRS
How do tetracyclines work?
inhibit bacterial protein synthesis by binding to the 30 S subunit of the ribosome
Weird facts about tetracycline’s to remember: (3)
- oral bioavailability is variable and influenced by food
- can concentrate intracellularly
- can concentrate in epithelial lining of the airways
What is the spectrum of activity of Tetracycline?
G+ and G- aerobes, some anaerobes
What is the route of administration of Tetracycline?
IM, IV, PO (in feed and water too)
What are some unique feature of the drugs Tetracycline and Oxytetracyline?
activity against intracellular pathogens:
- mycoplasm
- leptospira
What is the Spectrum of activity of Oxytetracycline?
G+ G- aerobes, some anaerobes
What is the route of administration for Oxytetracycline?
IM, IV, PO (also in feed and water)
What are some adverse affects of Ceftiofur?
V/D
hypersensitivity
Anaphylaxis
cytopenias
What are the Adverse effects of Tetracyclines?
tooth discoloration
rumen stasis (high PO doses)
hypersensitivity (swelling, dyspnea, collapse)
embryotoxic (early loss, later retarded bone growth )
What is the spectrum of activity for Chlortetracycline?
G- and G+, some anaerobes
What is the route of administration for Chlortetracycline?
primarily in feed and water
What is the MOA of Aminoglycosides?
bind to the 30 S subunit of bacterial ribosome impairing the proof reading ability of the ribosomal complex
Weird facts about Aminoglycosides: (3)
- not orally absorbed
- can causes ototoxicity, nephrotoxicity and neuromuscular blockade
- tissue residue for extended duration
What is the spectrum of activity for Dihydrostreptomycin?
G- aerobes only, Do not use for anaerobes
What is the route of administration for Dihydrostreptomycin?
IM, SC, intramammary
What is the spectrum of activity for Gentamicin?
G- and MDR staph sp, don’t use for anaerobes
Facts about Gentamicin: (3)
- Mechanism of action requires aerobic environment –> poor choice for anaerobics
- Highly water soluble, poorly lipid soluble –poor penetration of bile, prostate, brain, eye, CSF
- Highly concentrated in urine–> useful in some drug-resistant UTI
Route of admin for Gentamicin?
IV, IM, SC
What are the adverse effects of Gentamicin? (also same for Dihydrostrptomycin)
- Low therapeutic index, Monitoring plasma concentrations may be indicated
- Neprotoxicity (esp. treatment > 3days, elderly, prior renal impairment, dehydration, hyponatremia, hypokalemia, concurrent NSAIDs, liver impairment)
- Ototoxicity, vestibular toxicity
- Neuromuscular blockade w some anesthetics
What is the spectrum of activity for Neomycin?
G- aerobes, no anaerobes
What is the route of administration for Neomycin?
PO low oral bioavailability but used in cattle feed bolus for enteric infections with susceptible bacteria
What are the adverse effects of Neomycin?
Diarrhea
Rarely ototoxicity, nephrotoxicity
What is the MOA for the fluoroquinolones?
inhibit nucleic acid synthesis by inhibiting DNA gyrase and topoisomerase
What is the primary use for Fluoroquinolones?
treatment of BRD, specifically Pasturella multocida, Manheimia haemolytica, Hostophilus somni and Mycoplasma bovis
What is the spectrum of activity for Enrofloxacin? (Danofloxacin exact same)
G- and G+ aerobes, ineffective against anaerobes
What is the route of administration for Enrofloxacin?
SQ
Adverse Effects of Enrofloxacin/Danofloxacin?
- Hypersensitivity
- lameness (calves)
- SQ injection site reaction, arthropathy in rapidly growing animals.
What is the MOA of Sulfa drugs?
inhibit the enzyme involved in production of dihydrofolic acid which block bacterial biosynthesis of folic acid and the purines/pyrimidine’s needed for nucleic acid synthesis
Sulfa drugs are bacteriostatic or bacteriocidal?
Bacteriostatic
Spectrum of activity for Sulfadimethoxime? (same for Sulfamethazine, Sulfaquinoxaline)
G+, G- Aerobes, Poor anaerobe coverage
What are the routes of administration for Sulfadimethoxime? (same for Sulfamethazine, Sulfaquinoxaline)
PO IV (all trimethoprim are ELDU)
What are the adverse effects of Sulfadimethoxime? (same for Sulfamethazine, Sulfaquinoxaline)
- hypersensitivity
- depress rumen function (usually temporary)
- possibly teratogenic (disrupts development of fetuses)
What is the MOA of Macrolide?
binding 50 S subunit of bacterial ribosome and inhibiting peptide bond formation between specific combinations of amino acids
What is the spectrum of activity for Gamithromycin? (same for Tildipirosin, Tilmicosin, Tulathromycin)
Primarily G+, some G- bovine respiratory pathogens
What is the route of administration for Gamithromyacin? (same for Tildipirosin, Tilmicosin, Tulathromycin)
SQ
**main use for BRD (M. haemolytica, P. Multicida and H. Somni)
What are the advers affects of Gamithromycin? (same for Tildipirosin)
pain/swelling at injection site
What is the spectrum of activity for Tylosin/Tylvalosin?
Primarily G +
What is the route of administration for Tylosin? Uses?
IM
**used for BRD, foot rot, calf diptheria, metritis
Adverse effects of Tylosin?
Injection site reaction, anorexia. SEVERE DIARRHEA if used PO
What are the adverse affects for Tilmicosin?
- Injection in horses, goats, swine can be fatal (cardiotoxicity)
- IV injection in cattle, sheep can be fatal.
What are the adverse effects of Tulathromycin?
- Injection site reaction
- anorexia
- hypersalivation
- head-shaking
MOA of Lincosamindes?
bind to 50 S ribosomal subunit to prevent peptide bond formation
What are Lincosamides primarily used for?
-treatment of staphylococcal mastitis (eg staph aureus)
What is the spectrum of activity for Lincomyacin? (same for Pirilmycin)
G+ aerobes, good anaerobic coverage
What is the route of administration for Lincomyacin?
IM
Use in cattle in ELDU
Adverse Effects of Lincomyacin? (previous test question)
Do not give orally to fermenters and pigs
-Superinfection/death
Injection site reaction
What is the route of administration of Pirilmyacin?
(Lincosamide)
Intramammary
What are the adverse effects of Pirlilmyacin?
Extended therapy can increase risk of coliform mastitits
What is the drug class of Florfenicol?
Thiampheacol
**related to chloramphenicol and shares its MOA, spectrum and AE
used to treat BRD
What is the spectrum of activity for Florfenicol?
G+ and G-, aerobes and anaerobes, some rickettsia
Noteworthy affects of Florfenicol
Outstanding tissue penetration across tissues.
Combined preparation available with NSAID (flunixin)
Route of administration for Florfenicol?
SQ IM
Adverse affects of Florfenicol?
anorexia
dec. water consumption
diarrhea
injection site rxns
What drug class is Spectinomycin in?
Aminocyclitol (shares features with aminoglycosides)
What is the spectrum of activity for Spectinomycin?
G+, G- aerobes, mycoplasma. Poor anaerobic coverage
What is the route of administration for Spectinomycin?
SQ
What are some adverse affects of Spectinomycin?
well tolerated, can cause neuromuscular blockade
What do fluroquinolones treat in cattle?
Treats BRD:
- Pasturella multocida
- Manhemia hemolytica
- Histophilus somni
- Mycoplasma bovis