Exam 1 Flashcards
Lecture 1
Regulatory considerations for veterinary drug use
VCPR
Required to diagnose, prescribe medication, or treat.
Required for feed directives
- Veterinary medical judgements..
- Sufficient knowledge of the patient…
- Client agrees to follow recommendations
- Veterinarian available for follow up evaluation, emergency arrangements, etc
- Veterinarian provides oversight of treatment
- PE performed, keeping care.. timely visits..
- Patient records maintained
Consent form
Telemedicine
-AVMA opposes remote consulting in the absence of VPCR
-VPCR can not be established solely via electronic means
-Exception in emergency, toxicosis
-General and nor specific diagnosis, treatment
AMDUCA and ELDU
Animal Medicinal Drug Use Clarification act & ELDU
-Veterinarians may use approved animal and human drugs for therapeutic purposes in an extra label manner so long as there is no threat to public health
-An approved human drug for treatment can be used in an extra label manner when an identical, approved animal drug exists
-Extra label for another animal species only if there is no approved drug in that species or can not be found to be clinically effective
-Extra label use without VPCR is illegal in all animals
-ELDU use of approved drug in a manner that is nor in accordance with the approved labeling: another species, different indication, different dose or frequency, different route
Veterinary Feed Directive
-Outlines process for use of medically important antimicrobials in feed when needed for specific animal health purposes
-Requires VCPR
Regulatory requirements for prescribing drugs
-State Boards and Pharmacy regulate how meds are dispensed to the public
-Most states have laws requiring veterinarians to provide prescriptions upon request
-AVMA veterinarians shall honor a client’s request for a prescription in lieu of dispensing in clinic
Prescription writing examples
Off site pharmacy
-Include name of owner and name of patient
-Cephalexin 250 mg -Give 1 capsule PO every 8 hr until gone #21-no refills
-May want to include dispense as written, no substitutions
On prescription label in clinic
-Cephalexin 250 mg -Give 1 capsule by mouth every 8 hr for 7 days (or until gone). Discontinue if any vomiting or diarrhea.
Medical Records
-Ok to shorthand
-Cephalexin 250mg -Give 1 cap PO TID x7d #21.
-Must document in “plan” of SOAP
Regulatory requirements for controlled substances
Opioid prescribing limits in clinic
Schedule II-V
If dispensing controlled substances > 7days, then required to report
Schedule II
-Prescription signed
-6 months limit
-No refills
-No federal quantity limits dispensed via a prescription
Schedule III-V
-Prescription may be communicated orally in writing or electronically (not email) or by fax to the pharmacist
-Refills allowed with certain limitations
-Veterinarians do not have NPI: national provider identifier
-Write “dispense as written” or “ no substitutions” report pharmacists that make changes to your prescription
DEA
-DEA license
-Diversion control
-Top violations: poor record keeping, failure to prevent diversion, lack of physical security, registration issues.
-Create SOP, readily retrievable files, inventory biennial
Compounded medications for companion animal
-Must have a VCPR
-Use evidence-based medicine
-Limited for no other method or route of drug delivery is practical
-Safety, efficacy, stability demonstrated in target species
-Disease conditions monitored
FDA
-Permits.. when the source of the active ingredient is a finished FDA-approved drug and not a bulk drug substance
-Compounds from bulk drug substances not approved
-Food animals: evidence supporting drug residues in edible tissues
Post-market controls lacking, no report of adverse effects, stability or product quality
GFI#256
-Does not allow veterinarians to have office stock drugs to dispense from bulk drug sources due to safety concerns
-However allowed urgent use to avoid animal suffering and death
Lecture 2
Adverse drug reaction and Drug regulation
Regulation of animal drugs
Agencies
FDA
-protect public health
-safety, efficacy and security of human and veterinary drugs, biological products, medical devices, food supply, cosmetics, products that emit radiation
USDA-APHIS
-Veterinary biologics
-Vaccines, bacterias, antisera, diagnostic kits, and other biological products for diagnosis, prevention, treatment
-Pure, safe, potent, effective
EPA
-Topically applied parasiticides without systemic activity
-Animal facility insecticides/parasiticides
State Pharmacy Boards
-May elect to schedule drugs that are not federally scheduled
State Veterinary Boards
-Regulation lobbing
Drug approval process (FDA, USDA, EPA)
Sponsor: responsible for collecting and submitting all info to the FDA
FFDCA (federal food, drug and cosmetic act): includes in man or animal “articles” is other than food affect any function of the body man or animal
NADA (new animal drug application)
-Safety to the animal
-Safety to the products made from the treated animal
-Effectiveness of the drug
-The drug does not have and adverse environmental impact
-Drug safe to the people administering or coming in contact with the drug
Process
NADA 5-major sections
1. Target animal safety
2. Effectiveness
3. Human food safety
4. Chemistry, manufacturing and controls
5. Environmental impact
Minor sections
1. Labelling
2. All other information: studies that were conducted, experience from other countries
- Sponsore presents NADA packet to FDA
- FDA approval or not
- After approval notice published in federal registry
- Sponsor can sell the drug
Over the counter vs. Prescription
-All drugs go through the same process
-FDA determines if oversight necessary, if yes = Rx or VFD
Generic animal drugs
-Abbreviated New Animal Drug Application (NADA)
-Active ingredient, strength, dosage form, dosage regimen and route of administrations
-Must prove bioequivalence
-Generic labelling must match approved brand name
Freedom of information request to find approved drugs Animal drugs@FDA
Full approval
-Substantial evidence of efficacy
Conditional approval
-Reasonable expectation of effectiveness
-Allows drug company to sell it while gathering more evidence
Major species
-Food animals: cattle, pigs, chickens
-Dogs, cats, horses
Adverse reporting
Related to
- Dose dependent
- Dose independent
OR Type A-G
A. Augmented
-Adverse event reports are expected but exaggerated pharmacologic or toxicologic response to drug, extreme toxic response
B. Bizarre
-Unexpected responses
-Unrelated to the drug’s normal pharmacologic effects
-Allergic responses
-Dose independent
C. Chronic
-Occur from prolonged drug administration
D. Delayed
-Occur sometime after treatment
-Difficult to diagnose
-Ex: hair loss second to cancers, chemotherapeutic drugs
E. End of treatment
-Occurs when drug is discontinued abruptly
-Usually related to pharmacodynamic tolerance
-Ex: acid rebound following discontinuation of PPI or H2 blockers
F. Failure
-Under reported
-Lack of expected efficacy
-Ex: antibiotic resistance
G. Gaffes
-Result from human error and mostly involve oversight and overdose
-Ex: failing to put the correct decimal place in the correct place
Adverse Event Reporting
-CVM uses it to recognize potential risks and make decisions about product safety, which may include changes to label or other regulatory action
Submission by CVM
-FDA approved or indexed product: contact the company and they directly report it
-Or FDA form 1932a
-Unapproved: FDA form 1932a
Extra label drug use
AMDUCA
Compounded drugs
Extra label
-Different dose
-Different route
-Different species
-Different indication
Limitations
-Lay person but under the supervision of a veterinarian
-No on an animal feed
-Residue that may present a risk to the public health
-Residue above established safe level, concentration, or tolerance
Food animal
Zero tolerance
-No approved food animal drug
-Dx and evaluation of the condition
-Established extended withdraw times: Zero tolerance for ELDU
-Institute procedures to assure the animal’s identity is maintained
-Take appropriate measure to assure that assigned withdraw times are met and no legal residues occur
AMDUCA General Prohibitions
Extra label use prohibited in food-producing animal if
- An acceptable analytical method needs to be established and such method has not been established
- The extra label use of the drug or class of drugs presents a risk to the public health
Compounding
-Does not permit animal drug compounding from active pharmaceutical ingredients (bulk drugs). Exception for antidotes that are not available
-Active ingredient has to be FDA approved
Lecture 3
System specific antimicrobial considerations
Bacteriostatic vs. Bactericidal Examples & applications
Bactiriostatic
BANF
Bacteriostatic
STMC
Antimicrobial principles in clinical cases
Breakpoint
-MIC of a drug selected to predict clinical outcome
-Specific pathogen
-Specific disease
-In a specific species
-Given via specific regimen
-S: susceptible
-I:intermediate
-R: resistant
-NI: no interpretation
Do not have all breakpoints for veterinary diseases nor all species
Dose Regimen Determination
Time dependent antimicrobials
-Beta lactams: time above MIC, Gram (+) 50% of dosing interval >MIC, gram (-) 100% of dosing interval > MIC
Dose dependent antimicrobials
-Aminoglycosides: concentration >MIC, Max 8-10x MIC. Once!
Dose Regimen Determination
Fluoroquinolones
-Enrofloxacin: AUC > 125x MIC
The PK/PD Approach to therapy
For concentration dependent killers
-More can be better
-Weigh against toxicity concerns
-Ex: Amikacin, Gentamicin
For time dependent killers
-More frequently is often better
-Client compliance a problem
-“long-acting” formulations
-High protein binding
-Ex: Ceftiofur, Cefovecin
GI and Liver AM
Causes Parasitic vs. dietary vs. viral. vs. bacterial
Probiotics may be more effective than metronidazole for acute canine diarrhea
Infectious GI Disease
Small animals
Typically gram (-)
-Oxytetracycline
-Enrofloxacin
-Metronidazole
-Tylosin
Large animals
-Sulphonamides
-Gentamicin (pigs)
-Broad spectrum AM
Both: salmonella and E. coli AMR common
Liver
Small animals
Babes canis, Cytauxzoon felis
-Azithromycin
-Metronidazole
-Clindamycin
-Doxycycline
-Imidocarb or atovaquone
Clostridium novyi (Black disease) in cattle
-Anaerobic microenvironment from fluke migration in liver
-Beta-lactams
Skin Infection AM
Gram positive aerobes
-Staphylococcus intermedi, Staphylococcus aureus, MRSA, MRSP.
Gram negatives
-Pateurella multicocida
-E. coli, Proteus spp. Psuedomonas spp.
Rarely
-Actinomyces
-Nocardia
-Mycobacteria
-Actinobacillus
Topical therapy
-Decreased risk of AMR development
-Cost compared to systemic therapy
-Useful in recurrent/resistant pyoderma
-Problem: compliance, residues, odors, barriers of the skin inhibit penetrance
Topical Antimicrobials
- Benzoyl Peroxide
-Damage bacterial cell membrane
-Keratolytic
-Irritating and drying - Ethyl lactate
-Lowers skin pH
-Keratolytic
-Less irritation and drying
-Long term use
Others
-Mupirocin: Staphs
-Nisin: Broad-spectrum
-Amikacin + Gentamicin
-Enrofloxacin
-Silver sulfadiazine
Systemic
-Staph intermedius isolates: cephalosporins, cloxacillin, amoxicillin-clavulanate, chloramphenicol, TMS. Often resistant to amoxicillin, ampicillin, tetracyclines, sulfonamides
-Staphylococcus and P. multocida in cats: amoxicillin-clavulanate, cefovecin. Chloramphenicol caution in cats!!
Hemolymphatic system AM
Most are intracellular bacteria or erythrocytes
-Moderate to high volume of distribution and penetration needed
-Mechanism of action should not primarily be inhibition of cell wall synthesis
-Consider protein synthesis inhibitors or DNA-based: Tetracyclines, fluoroquinolone, chloramphenicol
Dogs:
Bartonella henslae, Ehrlich, Borrelia
-Doxycycline, macrolides, amoxicillin.
Cats
-Fluoroquinolones
-Tetracyclines
Llamas/Alpaca
-Oxytetracycline not likely to eliminate infection
Horses
-Oxytetracycline (Anaplasmosis, Potomac Horse fever Neorickettisa risticii)
Cattle
-Oxytetracycline (Anaplasmosis A. marginale)
Lecture 4
Small Animal GI Pharmacology Overview
MOA
Biological target
Tx plan
Adverse effects
Emetic Reflex
Anti Emetic Drugs
Chemoreceptor trigger zone (CTZ)
-Ondansetron
-Metoclopramide
Vestibular apparatus
-Maropitant
-Dimenhydrinate
Emesis gut
-Metaclopramide
-Isopropamide
Periphery
-Ondansetron
-Metoclopramide
-Isopropamide
Solitary tract nucleus
-Odansetron
-Metoclopramide
-Maropitant
Vomiting center (medula)
-Maropitant
-Atropine
Higher center (cerebrum)
-Scopolamine
-Dimenhydrinate
Ondansetron
MOA: Serotonin receptor antagonist, 5-TH2
Biological target
Tx plan: pre-surgical, parvovirus, chemotherapy emesis aid. Can be added to Maropitant
Adverse effects
Phenothiazines - Antiemetic
Ex: Chlorpromazine, Mepazine, Prochlorpromazine, Acepromazine
Adverse effects: sedation hypotension, caution with epileptic dogs
Metaclopramide - Antiemetic
MOA: Dopamine receptor antagonist dogs>cats effectiveness
Biological target: CTZ, pro kinetic effects 20x as potent as phenothiazines
Tx plan: duodenal pyloric relaxation, increased esophageal sphincter tone
Adverse effects
Maropitant - Antiemetic centrally acting
MOA: Neurokinin-1 receptor antagonist
Biological target: Blocks action of substance P
Tx plan: 1mg/kg SC
Adverse effects: pain on injection is common, bone marrow hypoplasia in puppies <8 weeks
Emetic Drugs - Dogs
Dopamine receptors stimulate CTZ > cats
Apomorphine
MOA: opioid agonist
Biological target: Stimulates CTZ
Tx plan: Conjunctively best (eye) 6.25 mg tab-dissolved in sterile solution IV or SC
Adverse effects
Ropinirole
MOA: Dopamine agonist
Biological target: stimulates CTZ
Tx plan: Eye drop. 3.75mg/m2 can do a second dose
Adverse effects
3% Hydrogen Peroxide
MOA: Local irritant leading to emesis
Biological target
Tx plan: 2.2 ml/kg (1ml/lb) PO max 45ml, can repeat second dose.
Adverse effects
Emetics - Cats
Alpha-2 receptors in the CTZ
Xylazine
MOA: alpha-2 adrenergic agonist
Biological target: stimulates CTZ
Tx plan: 0.44mg/kg IM. Reversal yohimbie
Adverse effects
Dexmedetomidine HCL
MOA: alpha-2 agonist, CNS depression. Reversal Atipamezole
Biological target
Tx plan: 7ug/kg IM
Adverse effects
Appetite stimulants
Capromerelin - Cats also
MOA: mimics endogenous gherkin hormone
Biological target: Triggers release of growth hormone and insulin-like growth factor-1
Tx plan: 3mg/kg SID (2mg/kg cats)
Adverse effects: wide margin of safety, discontinue if no response in 5 days
Mirtazapine - Cats also
MOA: anti-depressant antagonist of serotonin (5-TH2ac and 5TH3)
Biological target: appetite stimulation and antiemetic. Antagonizes H1 histamine and presynaptic alpha-2 receptors
Tx plan: 3.75 mg/dog PO (1.88 mg/kg cats)
Adverse effects: do nor use with other selective serotonin reuptake inhibitors (SSRI’s) such as fluoxetine, metoclopramine, erythromycin, cimetidine. Decreased renal and liver clearance in cats
Cyproheptadine - CATS only
MOA: antihistamine H1 receptor antagonist and SSRI’s
Biological target: inhibits serotonergic receptors which control appetite
Tx plan : 2-4 mg/cat PO SID-BID
Adverse effects: sedation, increased HR, dry MM
Antacids - Acid titrating Drugs
- Aluminum hydroxide
- Magnesium hydroxide
- Calcium carbonate
MOA: lack systemic effects, locally decrease pepsin activity, bind to bile acids and stimulate prostaglandin synthesis
Biological target: gastric ulcers, esophageal reflux
Tx plan: based on anecdotal experience is 5-10 ml q4hr
Adverse effects: constipation, binds to tetracycline, fluoroquinolone, digoxin (give meds 2hrs prior to antiacid)
Gastric Acid Secretion Inhibitors
H2-Receptor Antagonist
Famotidine»>Ranitidine>Cimetidine
MOA: competitive inhibitors at H2 receptor of the parietal cell
Biological target: decreased acid secretions induced by feeding, increase intraluminal bicarbonate, mucus secretion and mucosal BF, Ranitidine has pro kinetic effects
Tx plan: 30 minutes prior to meal with pancreatic enzymes to improve efficacy
Adverse effects: Cimetidine decreased drug metabolism due to inhibition of P450 enzymes, tolerance/tachyphylaxis
Gastric Acid Secretion Inhibitors - Proton Pump Inhibitors
Omeprazole, Esomeprazole, Iansoprazole
MOA: H+/K+ ATPase blockage on the luminal side of the parietal cell. most potent gastric acid inhibitors causing long-lasting and pronounced decreased in acid secretion
Biological target: erosive esophagitis, GI ulcers due to NSAIDs, mast cell tumors and gastrinomas
Tx plan
Adverse effects: rebound hyper secretion of gastric acid; intestinal dysbiosis possible, CP450 liver enzymes inhibition = longer half life of other drugs
Prostaglandin Analogs
Misoprostol
MOA: synthetic PGE2 analog, specific activity for parietal cell receptors and decreases histamine, pentagastrin, and meal stimulating gastric secretion
Biological target: prevention and treatment of NSAIDs ulceration, increases gastric mucus and bicarbonate production
Tx plan
Adverse effects: stimulation of intestinal motility and secretion, resulting in diarrhea and uterine contractions contraindicated in pregnancy
Mucosal Protectant
Sucralfate
MOA: multifactorial, acidic environment forms viscous gel with protein from damaged mucosa acting as diffusion barrier, adsorption of bile salts, inactivation of gastric pepsins
Biological target: Esophagitis, GUE
Tx plan
Adverse effects: safe, constipation, caution with renal failure, coadministration with doxycycline, ciprofloxacin, theophylline significantly decreases bioavailability give 2 hours prior to sucralfate LIQUID SUSPENSION not tablets
-No evidence of combining PPI and Sucralfate effectiveness increased
Consensus statement
- Gastroduodenal ulceration and erosion
-PPI’s BID dogs & cats - Gastritis
-No evidence to support prophylactic use with non-erosive gastritis - Stress-related mucosal damage
-Prophylactic PPIs
-Specially competing animals - Reflux esophagitis
-PPI’s may not decrease gastric reflux but may prevent injury by increasing pH - Helicopbacter
-PPI’s not indicated
Antibacterial
Metronidazole
MOA: bactericidal, anaerobe coverage, antiprotozoal effect
Biological target: Giardia spp, Helicopbacter, Clostridium, diarrhea
Tx plan: as needed
Adverse effects: neurotoxicity (tx with diazepam) ataxia, disorientation, seizures
Tylosin
MOA: Macrolide, 50s Ribosome, inhibits protein synthesis
Biological target: ARE, IBD
Tx plan
Adverse effects: safe, increases digoxin levels, bad taste
Enrofloxacin
MOA: fluoroquinolone with broad spectrum, bactericidal, histolytic ulcerative colitis in boxers
Biological target: DNA inhibition
Tx plan
Adverse effects: V/D, cartilage damage in <28wks old, retinotoxicity in cats lower dose
Sulfasalazine - Anti-inflammatory, Antibiotic
MOA: Sulfapyridine-5-aminosalicylic acid compound that is broken down in the colon. Competitive antagonist for aminobenzoic acid.
Biological target: IBD in dogs
Tx plan
Adverse effects: Allergic reactions, appetite loss, KCS, caution in cats!
Prokinetic Drugs
Metaclopramide
MOA: central and peripheral antidopaminergic (antiemetic) effect and direct and indirect stimulator of cholinergic receptors
D2 and 5-HT4 receptors activity = pro kinetic
Biological target: UPPER intestinal tract limited. Accelerated gastric emptying post ileus
Tx plan
Adverse effects: extrapyramidal antidopaminergic effect, tremors, relentlessness in dogs, not seen in cats
Cisapride
MOA: Activates acetylcholine release from the mesenteric plexus stimulating GI and smooth muscle. Dose dependent, activity from esophagus to colon
Biological target: Manage chronic constipation and mega colon in cats
Tx plan
Adverse effects: Do not combine with drugs that inhibit CP450 such as Itraconazole, Ketoconazole = fatal arrhythmia, needs to be confounded.
Bismuth subsalicylate caution in cats
Laxatives and Cathartics
Emollient laxatives
-DDS
Simple bulk laxatives
-Phyllium
Osmotic Cathartic
-Lactulose
Irritant cathartic - not recommended
Enemas
-Warm water with mild surfactant nor phosphates!
Anti-inflammatory drugs for IBD
Glucocorticoids
Budisonide
Cyclosporine
Chlorambucil
Axathioprine - not in cats!
Probiotics
Parietal Cell GI Receptors & Drugs. All drugs
