Therapeutics in Disease Management Flashcards
prescription drugs
anything with a label that states:
only use on approval by licensed veterinarian
over the counter drugs (OTC)
can be purchased and administered (according to label directions) without a prescription
AMDUCA
Animal Medicinal Drug Use Clarification Act
provides veterinarians acting within
a veterinarian-client-patient relationship (VCPR) with
greater prescribing and dispensing options so that
animals can receive the medications they need when
they need them. This is critical given the relatively few
numbers of drugs labeled for use in animals
ELDU
-guidelines for the Extra Label Drug Use
the term that describes
the use of an approved drug in a manner that differs
in any way from the drug’s approved labeling. This
includes deviations from FDA-approved labeling such
as using the drug in any of the following ways.
Important points
ELDU permitted only under veterinary supervision
ELDU for therapeutic purposes only
ELDU is prohibited for drugs used in feed.
ELDU cannot be applied to drugs used to
enhance production
In a species not listed on the label
For an indication not listed on the label
At a different dose or frequency than listed on
the label
Via a different route of administration than listed
on the labe
difference between previcox and equioxx
Previcox is a pill labeled for use in dogs, Equioxx is labeled for use in horses.
FARAD
Food Animal Residue Avoidance Databank
veterinarians who treat food animals with drugs
in an extralabel manner must use evidence
“…derived from food safety data or other
scientific information…” in order to determine an
appropriate withdrawal interval (WDI) that allows
for a conservative estimate of drug residue level
in edible animal tissues.
drugs prohibited for use in food producing animals
Chloramphenicol Clenbuterol Diethylstilbestrol Pronidazole Dipyrone Other Nitroimidazoles Furazolidones & Nitrofurazone(except approved topicals) Major vs minor food animal species
can you use sulfonamides in dairy cattle
Currently, use of
any sulfonamide other than SDM in dairy
cattle older than 20 months is illegal.
Additionally, extralabel use of SDM in
lactating dairy cattle is prohibited (for
example, use of a higher dose or slow-release
SDM boluses in dairy cattle is not permitted).
glycopeptide antibiotic
vancomycin- used for treatment of MRSA in humans and used in european feeds as a growth promoter.. no prohibited
which two drugs are not currently prohibited in dairy cattle but result in “debits”
dimethyl sulfoxide
collodial silver
VFD
veterinary feed directive
-Developed in response to microbial resistance issues associated with our livestock animals.
-Removal of OTC available
antibiotics. (medically important)
-Veterinary oversight of antibiotic use
in feed and water.
Documentation at the veterinary,
owner, and feed mill levels.
Beef/Dairy Quality Assurance
Prevent inappropriate:
- Biologics
- Therapeutics
- Handling
Quality Assurance (goals)
- residue avoidance
- improve milk/meat quality
- minimize injection size lesions
Dairy Quality Assurance
Dairy Quality Assurance Handbook
Voluntary use vs. mandatory use
Some states offer incentives if a dairy goes
through the handbook on a voluntary basis
Concepts very similar to BQA
Additional measure beyond BQA include
residue avoidance in fluid milk, appropriate
storage of lactating and non-lactating cow
therapeutics, accordance with the
Pasteurized Milk Ordinance (PMO), etc.
Dairy animals => meat processing.
National Cattleman’s Beef Association’s BQA- National Guidelines
Feedstuffs
- Maintain records of any pesticide/herbicide
use on pasture or crops that could potentially
lead to violative residues in grazing cattle or
feedlot cattle.
- Adequate quality programs are in place for
incoming feedstuffs.
- Analyze suspect feedstuffs prior to use
- Ruminant-derived protein sources cannot be
fed (FDA)
- Feeding by-product ingredients should be
supported with science
Feed additives and medications: Only FDA approved medicated feed additives will be used in rations Medicated feed additives will be used in accordance with the FDA Good Manufacturing Practices (GMP) regulations Extra label use of feed additives is illegal and strictly prohibited VFD
extralabel use of medicated feed
AMDUCA specifically prohibits the “extralabel use of an approved new animal
drug or human drug in or on an animal feed.”
Withdrawal times must be strictly
adhered to
Complete records must be kept when formulating or feeding medicated feed rations
Records must be kept for a minimum of 2 years
Operator will assure that all additives are withdrawn at the proper time to
avoid violative residues
processing/treatment and records
Follow all FDA/USDA/EPA
guidelines for products used
Use all products as per label directions
Extra label drug use shall be kept to a minimum, and used only when prescribed by a veterinarian working under a Valid Veterinary
Client Patient Relationship (VCPR)
All cattle (fed and non-fed) shipped to
slaughter will be checked by appropriate
personnel to assure that animals that have been treated meet or exceed label or prescription withdrawal times for all animal health products administered.
All processing and treatment records should
be transferred with the cattle to next production level. Inform buyers of cattle which have not met their withdrawal time.
maintenance of treatment records
Individual animal or group identification Date treated Product administered and manufacturer’s lot and serial # Dosage used Route and location of administration Earliest date animal will have cleared withdrawal time
injectable animal health products
Injectable animal health products
Products labeled for subcutaneous(SQ)
use should be administered ahead of the shoulder
All products labeled for intramuscular(IM) use shall be given in the neck region only.
All products cause tissue damage when injected IM, therefore IM usage should be
avoided.
Products cleared for SQ, IV or oral administration are recommended
where do you never inject?
the hindquarters
products with what size dosage are recommended?
low
no greater than 10 ml should be injected per IM injection site
correct needle size is important
SQ= 16 or 18 gauge
IM= 16 or 18 gauge
14 gauge is not recommended
why is 14 gauge not recommended?
increases tissue trauma
more likely to get drainage from the site
care and husbandry practices
All cattle will be
handled/transported in such a
manner as to minimize stress, injury and/or bruising.
Facilities should be inspected
regularly to ensure proper care and ease of handling
Strive to keep feed and water handling equipment clean.
Provide appropriate nutrition and feedstuffs management
Strive to maintain an environment
appropriate to the production
setting
Bio-security should be evaluated
Records should be kept for a minimum of 2 years (3 for restricted use pesticides).
handle vaccines and medications with care
Store in refrigerator
Don’t mix two different products in same
syringe
Use separate needles for filling syringes and
injecting (minimizes product contamination
and maintains use of sharp needles)
Sanitation is essential
Disinfectant residues in syringes can inactivate MLV vaccines
antimocrobial therapy
Antimicrobial- kills microorganisms or
inhibits their multiplication/growth
Antibiotics – a chemical produced by a
microorganism that has the ability in dilute solutions to inhibit microbial growth or kill microorganisms
minimum inhibitory concentration (MIC)
the lowest concentration of drug that inhibits bacterial growth (kills 99.9% of the bacteria)
bactericidal
an antibiotic have a MBC:MIC ratio < 4:6
bacteristatic
inhibits bacterial growth
post-antibiotic effect
persistence of anti- microbial activity after drug concentrations have fallen below MIC
pharmacokinetics
the study of absorption, distribution, biotransformation, and excretion of drugs
pharmacodynamics
the study of the effects of drugs, mechanism of
action (MOA), and concentration-effect relationships
MIC determination
Measures the minimum concentration of
each antimicrobial agent
(microgram/ml) that is inhibitory for a given bacterial isolate.
Dilutions of each antibiotic are incubated with a standard number of bacteria; bacterial growth is measured over time.
Comparison of above concentration
with that achievable in tissue = susceptible or resistant.
Antimicrobial Sensitivity Testing
Agar Disk Diffusion
Kirby-Bauer Disk Diffusion Test Meuller-Hinton Agar Paper disk impregnated with antibiotic Diameter of zone inhibition is measured and correlates to the MIC Interpretation – not standardized for veterinary medicine
problems with sensitivity testing
Overestimates antimicrobial activity
in CSF, prostatic fluid and udder
Underestimates antimicrobial activity
in topical treatments, local infusions, and urine
Underestimates activity at
concentrations < MIC
Assumes plasma and tissue concentrations are equal
Doesn’t assess combination therapy (synergistic effects)
Cannot assess local factors
that influence antimicrobial
activity
inhibitors of cell wall synthesis
beta-lactam antibiotics
penicillins
cephalosporins
benzylpenicillin
procaine pencillin G (PPG), benzathine penicillin, potassium penicillin
aminopenicillins
ampicillin, amoxicillin
anti-staphylococcal penicillins
cloxacillin (Dariclox)
which generations of cephalosporins do we use
1st and 3rd generations
inhibitors of protein synthesis
aminoglycosides tetracyclines chloramohenicols macrolides lincosamides sulfonamides
inhibitors of nucleic acid synthesis
fluroquinolones (Baytril)
penicillin use
many pyogenic infections in ruminants, camelids, and swine
withdrawal time for penicillin
milk-120 hours, meat- 30 days
uses for aminopenicillin
foot rot, shipping fever, mastitis
withdrawal time for aminopenicillins
amoxi-inject: milk- 96 hours, meat: 25 days
polyflex: milk- 96 hours, meat- 6 days
amoxi-mast: milk- 60 hours, meat: 12 days
cephalosporins (1st generation) uses
lactating and dry cow mastitis pathogens
cephalosporins (1st generation) withdrawal time
Cefa-Lak, Today (milk
– 96 hrs., meat – 4 days), Cefa-Dri,
Tomorrow (milk – 72 hrs., meat – 42 days)
cephalosporins (3rd generation) uses
shipping fever
cephalosporins (3rd generation) withdrawal times
Naxcel (milk – 0
days, meat – 0 days), Excenel (
milk – 0 days, meat – 48 hours)
dihydrostreptomycin uses
dry cow treatment
dihydrostreptomycin withdrawal times
Quartmaster (Dry cows,
Meat 60 days)
oxytetracycline uses
Shipping fever, Wooden Tongue, Pinkeye,
Foot Rot, Diphtheria, Bacterial enteritis,
Leptospirosis, Wound infections, Acute metritis
oxytetracycline withdrawal times
LA-200 (milk – 96 hrs., meat –
28 days); varies according to formulation, dose
and route of administration.
florfenicol uses
shipping fever
forfenicol withdrawal times
Nu-Flor(meat 28-38
days) Not approved for use in lactating
dairy cattle
erythromycin uses
lactating and dry cow mastitis pathogens;
metritis; foot rot; Pneumonia ( Shipping fever)
erythromycin withdrawal times
Erythro-100,200(milk – 72 hrs., meat – cattle 14 days, sheep 3 days, swine 7
days); Erthro-36, Dry (milk – 36 hrs., meat – 14 days)
tylosin uses
shipping fever Mycoplasma
pneumonia, foot rot diphtheria, metritis,
swine dysentery, Erysipelothrix
tylosin withdrawal times
Not approved for use
in lactating dairy cattle; meat-cattle 21
days, Swine 14 days
tilmicosin uses
shipping fever
tilmicosin withdrawal times
Not approved for
use in lactating dairy cattle, meat – 28
days.
lincocin uses
Swine – arthritis, Mycoplasma
pneumonia
lincocin withdrawal times
slaughter 48 hours (swine)
pirlimycin uses
gram positive mastitis pathogens
pirlimycin withdrawal times
milk- 36 hours, meat- 28 days
sulfadimethoxine uses
Foot Rot, Pneumonia, Corybacterium,
Salmonella
sulfadimethoxine withdrawal times
Albon(milk – 60 hrs., meat – 7 days), Albon SR (not for use in lactating dairy
cattle; meat - 21 days)
enrofloxacin uses
Only approved livestock use is for the treatment of pneumonia in cattle.
enrofloxacin withdrawal time
not for use in lactating
or preruminant dairy calves, meat – 28 days.
antimicrobial resistance
Emergence of resistant strains of bacteria is
a major potential public health risk.
Bacteria have two types of genetic
structure through which resistance can be
conferred
Chromosomes
Plasmids (extrachromosomal) (R-factors)
chromosomes in antimicrobial resistance
-Depends on mutation of bacterial genes
-Antimicrobial compounds act as selective agents that
allow resistant mutants to emerge
plasmids in antimicrobial resistance
-Acquired: Insert into bacterial genome
-Plasmids may contain 20 – 500 genes that carry
resistance to a number of antimicrobial agents (Multidrug Resistant strains.)
three areas of concern for antimicrobial resistance
Intestinal infections – reservoir of Rfactors may be carried by commensal
bacteria in the gut
The use of low levels of antibiotics (e.g
feed additives, or improper dosing) may lead to a high occurrence of R-factors in
the bacterial population
Indiscriminate use of
antibiotics=>eliminate effectiveness of antimicrobial substances in future
principles of rational antimicrobial therapy
Know your patient Know the infection Viruses don’t respond to antibiotics Location – tissue perfusion,etc. Culture and Sensitivity ( bacteria) Remove the pathogen or source if possible Select an appropriate antimicrobial agent and dose regimen Dose adequately Maintain the dosage Monitor treatment outcome Recording keeping Investigate therapeutic failures Recognize and address adverse drug reactions
inflammation
Immune cells distributed throughout the body
Need to focus the response to a specific site during
infection=>Inflammation
three major events of inflammation
Increased blood supply to infected region.
Increased capillary permeability permitting larger than normal molecules to breach the vessel wall (soluble mediators e.g.complement)
Leukocytes migrate out of venules into surrounding
tissue ( Diapedesis)
Neutrophils, Monocytes and Lymphocytes
anti-inflammatories
glucocorticoids
non-steroidal anti-inflammatory agents (nsaids)
glucocorticoids uses
Treatment of edema, insect
bites/stings, nerve injury, ketosis, and aseptic
laminitis. Termination of pregnancy.
glucocordicoid withdrawal time
none
NSAIDs uses
Control of pyrexia
(fever) associated with bovine respiratory
disease and endotoxemia and for control
of inflammation associated with endotoxemia.
Banamine
mechanisms of edema
Increased Vascular Permeability Decreased Plasma Colloid Oncotic Pressure Increased Hydrostatic Pressure Decreased Lymphatic Drainage
diuretics uses
Treatment of udder edema;
Label – treatment not to exceed 48 hours post-partum
diueretics uses withdrawal time
milk and meat 48 hours
Thaizide/Glucocorticoid
Combination use
udder edema
withdrawal for milk in 72 hours
side effect- abortion
other therapeutics
Reproductive Drugs Parasiticides Sedatives, Anesthetics and Tranquilizers Growth Promoting Hormones Fluid therapy
metaphylaxis
Term for the use of specific products (Mycotil,
tilmicosin) upon entry into feedlots
Data suggest beneficial effects (reduced
morbidity)
Administration on arrival (post shipment) was
superior to pre-shipment treatment*
More work…timing, other stresses, etc.
