pharamacology exam 2 Flashcards
1
Q
respiratory anti-inflammatory drugs glucocorticoids
A
-used for equine RAO, feline asthma and canine bronchitis:
* High dose, chronic oral glucocorticoids.
-steroids blunt inflammatory response.
-use lowest dose which will lead to effect. will lead to systemic effects after long term use.
2
Q
Beneficial effects of glucocorticoids on airway:
A
- ↓ severity of airway inflammatory symptoms
- ↓ airway response to ongoing allergens
- possibly prevent airway wall remodeling?
NET EFFECT: ↑ effective airway radius = ↑ airflow - ↓ recruitment of airway eosinophils (↓ leukotrienes)
3
Q
systemic glucocorticoids different species
A
- Prednisone: dogs at 1 mg/kg PO EOD (not good for cats/horses) they use prednisolone.
-methylpredisolone: watch for diabetes in cats
-Dexamethasone powder or injection for horses
4
Q
Inhalent (aerosolized) Glucocorticoids
A
Less systemic absorption, ↓ HPA suppression
* Fluticasone (Flovent®, generics)
* Most potent, longest acting
* Ciclesonide (Aservo EquiHaler): causes coughing and nasal discharge.
5
Q
best way to manage inflammatory airway disease
A
- Bronchodilators (b-2 agonists) = treatment of inflammatory airway disease signs
- Steroid = prevention of airway inflammation
-use these two together. use bronchodialator first to max absorption.
-must manage allergen from environment.
6
Q
mirtazapine mechanism of action
A
-Stimulates release of norepi
- Increases specific serotonergic (5-HT1) receptor activity?
* Potent antagonist of 5-HT2 receptor
* Likely cause of ↑ appetite
* Potent antagonist of histamine (H1) receptors
* Can result in sedation
7
Q
Mirtazapine doses
A
-increase appetite-polyphagia
-Mirataz 2% – transdermal gel placed on inner pinna of cat’s ear
Oral = generic human tablets (15 – 45 mg)
-dose =2mg/cat
-good in acute settings
-should work at 36 hr.
-causes vocalization and interaction behavior (less for transdermal)
8
Q
drug induced polyphagia as a side effect
A
-glucocoirticoids:* Typically observed more in dogs than cats
* Usually only a transient effect (days – weeks)
-anabolic steroids: (test) use in chronic illness with weight loss. controlled drugs now due to abuse.
9
Q
opioids for diarrhea and vommiting
A
- Anti-secretory and anti-motility effects by acting on μ (and other?) receptors in GI tract = constipation
- Loperamide (Imodium®, OTC) stays in gut causes constipation in healthy.
-Don’t use with infectious diarrhea or in known ABC-B1 deletion dogs
10
Q
Antimicrobial Therapy for diarrhea
A
-only for known bacterial causes.
-antimicrobials can cause diarrhea by changes to natural flora in gut. (nuflor, Baytril)
-only use when animals with bad inflamed diarrhea it breaks down mucosa and bacteria can get into blood. (ex neonatal calves without colostrum, parvo puppy) to manage secondary septicemia.
-beware OTC calf scours boluses, they don’t work.
11
Q
NSAIDS for diarrhea (not very useful)
A
-Meloxicam has label claim for calf diarrhea (w/ oral fluid therapy)
-ketoprofen, flunixin (when blood in feces)
-increase appetite due to feeling better?
12
Q
gastric mucous protection
A
-mucus layer coating cells
-tight junctions for no HCL passage
-mucosal cell membrane not permeable to HCL.
-Bicarb in mucos
-rapid cell turnover
-pepsinogen inactive from when secreted.
-need BF to stomach wall to make mucous ect.
13
Q
how acid is produced in stomach
A
-when pH goes up gastrin stimulates partial cells and proton pump produces acid. and Ach from eating. and histamine on H2 receptors.
-neg feedback loop when pH gets too low somatostatin comes in stops production.
14
Q
proton pump inhibitors for ulcers mechanism
A
-blocks acid production
-due to uncer there are less protective mechasnisms in that area
-blocks adenylate cyclase enzyme which stops acid production.
-stops proton pump of K for H ion.
15
Q
Omeprazole (Gastrogard®
A
-proton pump inhibitor
* Short T1/2, but long effect (irreversible inhibition)
* 4 mg/kg: for ulcer tx
* 1 mg/kg: prevent ulcers
Watch out for:
* GI ulcer relapse when off therapy
* Chronic gastric acid reduction leads to hypergastrinemia ( Mucosal cell hyperplasia, rugal hypertrophy, & carcinoids)
* CYP-enzyme inhibitor (watch for drug interactions)
-PPI in dogs and cats should be tapered after prolonged use > 3-4 weeks
16
Q
emetics
A
-Commonly used after toxin ingestion
-apomorphine
-a-2 agonists (emetic for cat IM) xylazine and dexmedetomadine. (50%)
-hydrogen peroxide
-saturated salt solution
17
Q
Apomorphine:
A
-Emetic (causes vommiting)
-dopamine agonist in CRTZ
◦ ~ 90% effective as emetic for dogs, less effective emetic in cats
◦ Administered in conjunctiva (eye) or IV
◦ Other opioids may induce vomiting too
◦ E.g., hydromorphone (anesthesia pre-med)
18
Q
Phenothiazine drugs (sedatives):
Acepromazine (Atravet®) – injectable and powder only
A
-anti-emetic
-Antagonizes dopamine:
* Inhibits the CTZ &/or emetic center
* Can decrease vomiting from other causes (e.g. motion sickness)
-antihistamine in dogs, weak anticholenergic cats.
-ADR: hypotension/ sedation, extrapyramidal signs (aggressive), seizures.
-good short form like car ride.
19
Q
Antihistamines (H1 blockers) as an anti emetic
A
- Block both cholinergic (cats) and histaminic (dogs)
nerve transmission responsible for transmission of
vestibular stimuli to the emetic center - Mild sedation, especially diphenhydramine
(Benedryl), dimenhydrinate (Gravol)
20
Q
Metoclopramide (injectable solution)
A
-anti emetic
* Low doses: inhibits dopamine in the CNS
* Peripheral prokinetic effect: increases gastric and
upper duodenal emptying
* High doses: inhibits serotonin receptors in the CRTZ
* Extrapyramidal effects (like acepromazine
-not used much now, older vets maybe.
21
Q
-Ondansetron (Zofran® & generics
A
-serotonin antagonsit
-very $$$
* Inhibit 5-HT3 (serotonin) receptors on vagal nerve & CRTZ
-great for chemotherapy vommiting!! not motion sickness or sickness.
- Cytotoxic drugs and radiation release serotonin
22
Q
Maropitant (Cerenia®, Emavert)
A
-big anti emetic drug in small animal
A neurokinin (NK1) receptor antagonist:
* Blocks binding of substance P (tachykinin) at emetic center
-blocks drug induce vommiting (apomorphone)
-labeled for acute vommiting (2mg/kg) and motion sickness
-maybe good as analgesic and anti-inflammatory
23
Q
Maropitant (Cerenia®) formula and adverse effects
A
Formulations:
◦ Oral tablets (labelled for dogs only)
◦ Injectable formulation (dogs + cats)
Adverse effects:
◦ Can cause bone marrow hypoplasia in young puppies
◦ So be careful with parvo dogs < 16 weeks
◦ Contraindication: suspected GI obstruction
Use in cats: effective for many causes of vomiting
◦ Dose at 1 mg/kg to start
◦ Long term use in cats
24
Q
Anti-emetics for Parvo-induced emesis
A
- “Metoclopramide, ondansetron and maropitant used as anti-emetic
drugs in the treatment of Parvoviral enteritis reduced the severity of
vomiting starting with the first day of treatment, and reduced the
number of vomiting starting with day 3 of treatment”
25
treatment of diarrhea (non drug)
Fluid therapy:
◦ Diarrhea doesn’t kill animal, dehydration & acidosis do
Electrolytes:
◦ Replace sodium, chloride, probably potassium
Acid/base treatment:
◦ Bicarbonate to treat acidosis
◦ Metabolizable substrates that produce bicarb
◦ citrate, propionate, acetate
26
how oral rehydration therapy works
-Fluids must contain – H2O, Na and a cotransporter (AA or glucose)
-Na has many ways to enter mucosa cell. water follows Na ions into the cell. you need glucose or amino acid as cotransporters to bring in water by osmosis.
27
Anticholinergic Drugs for diarrhea
* Significantly ↓ intestinal motility and secretions. only good for hypermotile diarrhea. (not many cases)
-side effect tachycardia and decreased gut sounds.
-Hyoscine butylbromide (Buscopan) used in collics to supress intestinal spasm in horses.
-some people use it for diarrhea but not effective.
28
Potassium Bromide (KBr)
* VERY old anti-epileptic drug (1857 in humans!)
* Likely hyperpolarizes neural cell membranes
-adverse effects in dogs: sedation, vommiting, diarrhea. polyuria and phagia. plevic limb weakness/ stiffness.(with bromide toxicity) not ataxia. pancreatitis, skin lesions.
-not recommended in cats! coughing and bronchial asthma.
29
Potassium Bromide Kbr pharmacokinetics
* Extremely long half life (24 d)
– Can use “loading” dose for first week
* 120 – 160 mg/kg (4x the maintenance dose)
– Once at steady state: missing single dose not critical
* Elimination: Renal (but reabsorbed with Cl-)
– No hepatic metabolism (so ↓ drug interactions)
30
Potassium Bromide Kbr food interactions/ overdose treatment
-no drug but has food interactions
-salt diet: decreases br reabsorption from renal tubule increases excretion so less br in blood.
-cardiac diets (low salt): increase Kbr in blood and reabsorption.
* Treatment of overdose
– IV 0.9% NaCl, 10 mL/kg/h for 12 hours
31
Diazepam (Valium®) treatment
-treat status epilepticus in cats and dogs Not generally used for seizure prevention.
-IV crosses BBB rapidly.
-rectal bioavaliability is 50% so give 2x dose. or intransal 80%
-dont use oral, low bio.
* Hepatic metabolism: two active metabolites:nordiazepam & oxazepam.
32
Diazepam: Adverse effects
* Lethargy, sedation, ataxia
– But as anticonvulsant: probably due to seizure, not diazepam
* Hyperactivity?
* Increased appetite (weight gain)
* Seizures may occur if abruptly stopping chronic diazepam
* Reports of fulminant hepatic necrosis in cats
– Idiosyncratic (not dose-dependent) reaction.
-use for prevention in cats not chronic!
33
newer anticonsolvent problems
Most efficacy studies with new(er) anticonvulsants:
* Typically administered as add-ons
* Non-controlled (no placebo)
* Typically small sample size
* Often not blinded
* Imprecise outcome measures (owner scores)
ex: Levetiracetam (Keppra®, gabapentin, cannabindoil.
34
Levetiracetam (Keppra®)
-added to PB or Kbr as added therapy. works good, not as great as sole therapy.
-Used for cluster seizures
– 20 mg/kg PO, TID
* Previous: Start at 10 mg/kg BID and work up
– High oral bioavailability
– Short T1/2 (3 – 4h)
– Renal excretion:
* Good choice if worried about hepatic disease
-tolerance after 4-8 months.
-fatal AE in dog after rapid iv injection
35
Brivaracetam
-anti consolvent
* Newer, more potent analogue of levetiracetam
* Single dose PK study performed in cats:
– Good oral bioavailability
– Plasma concentrations in therapeutic range for humans
– Longer T1/2 elim than levetiraceteam (maybe allows BID dosing?)
– Adverse effects mild (sedation, ptylalism)
36
Gabapentin as an anticonsolvent
– Structural analogue of GABA, but doesn’t appear to impact
GABA receptors!
* Block or modulate Ca
– May be given in combination with PB &/or KBr in dogs
– Frequent administration in dogs: 10 mg/kg TID
-sedation/ ataxia
37
Pregabalin (Bonqat®)
– Oral solution now approved as anxiolytic in cats before car transport
* NOT approved as anticonvulsant
-50% reduction in sieziers
-sedation/ ataxia
38
H2 receptor antagonists
-Block parietal cell HCl secretion through H2 receptor inhibition
-* Cimetidine (Tagamet®)
* Ranitidine (Zantac®)
Famotidine (Pepsid® AC)
-not much efficacy in dogs/ cats use PPI
-Orally absorbed, but low F in horses & ruminants
-Lipid soluble (Vd > 1 L/kg)
-Short T1/2 elim
-CYP inhibition: ↓ metabolism of other drugs: Cimetidine is notorious!
39
Anti-ulcer medication:
“Acid Rebound"
* Increase in parietal cell mass may occur
with chronic use of H2-blockers or proton pump inhibitors
* Increased serum gastrin and/or
upregulation of the H2-receptors
* Parietal cells more sensitive to histamine
40
Antacids
* AlOH, MgO / MgOH, CaCO3
◦ Maalox, Tums, Rolaids, etc.
* Neutralize stomach acid to form
water and a neutral salt
* Usually not absorbed systemically
-sucralfate: coats the ulcer
-don't treat ulcers with antimicrobials in animals
41
Misoprostol
-prostaglandin analogue
* Stimulates bicarbonate and
mucus secretion
* Increases mucosal blood flow
* Decreases vascular permeability
* Increases cellular proliferation
and migration
* Evidence of efficacy as a preventative for NSAID- induced ulcers in dog.
-causes abortion in humans
42
Exocrine Pancreatic Insuficiency
* Failure of exocrine pancreas to produce Lipase Amylase and
Tripsin for digestion of normal diet
* Mainly dogs
-treat with Pancrelipase (Pank-Aid)
* Supplement of exocrine pancreas enzymes
-mix with food before feeding to dog. wipe dogs mouth after eating can lead to ulcer on nose.
43
Treat constipation
* Lubricants: Mineral oil (cattle, horses)
* Mineral oil + white
petroleum (cats → hairball remedy)
-don't want in lungs will get limphoid pneumonia
- stimulant laxatives
-use hyperosmotic laxatives
-bulk laxatives increase fiber (cellulose) to increase bulk of fecal material.
-probiotics
-stool softeners, increase H2O
44
Treatment of constipation
* Hyperosmotic laxatives
-draw fluid into GI
lumen to stimulate motility
* Sodium phosphate enemas: don’t use in cats: Can cause hyperphosphatemia
* Lactulose
* Disaccharide - broken down but unabsorbed
* Polyethylene glycol (PEG) powder ~ ¼ tsp mixed in food for cats
45
motility modifying drugs
-used as prokinetics:
* Metoclopramide –upper GI
* Cisapride – lower & upper GI
-prokinetics as a side effect: * Erythromycin, azithromycin, Cimetidine,
46
Metoclopramide (injectable solution)
Motility effects: generally on UPPER GI tract
* Prokinetic effect: ↑ gastric & upper duodenal
emptying
* ↑ gastroesophageal sphincter tone
* Inhibits serotonin (5HT3) receptor: for anti-emetic effects
* Stimulates serotonin (5HT4) receptor: Accounts for prokinetic effect
-dont use with horses
-primary use: megaesophagus
-AE: make sure there is no GI obstruction.
47
Cisapride
* Mechanism of action:
* 5-HT4 agonist (lead to ↑ ACh in myenteric neurons
* Like metoclopramide, but likely more effective prokinetic
* Cats: ↑ smooth muscle motil. (stomach, small intestine, &
colon) Used for megacolon in cats
* Horses: treatment of ileus after abdominal surgery (IV use)
-dogs GERD
-not on market may be able to get compounded.
48
Erythromycin, Azithromycin, lidocaine
-Increased motility as a side effect
-Mechanism: Thought to activate motilin receptors in
stomach and proximal small intestine
* May have effect on distal GI tract in cattle & horses
* Erythromycin:
* Oral administration can cause vomiting and regurgitation (not good in horses)
-Lidocaine
* Used in horses to reduce post-op ileus-ADR: ataxia, seizures
49
Benzimidazole Mechanism of Action
* Binds to parasite β-tubulin subunit (microtubule) and disrupts cell processes and internal skeleton, leads to cell death
* ↑ drug-parasite exposure time correlates with efficacy (longer exposed to drug better drug works)
-very safe: uncommon bone marrow hypo, after prolonged high dose in puppies.
50
Benzimidazole Pharmacokinetics
-low oral bio, high distribution
-extensive hepatic metabolism (has 1st pass effect if oral) also metabolism in other tissues (lung, intestines)
51
Fenbendazole: a benzimidazole
-licensed for use in horses, cattle, swine and dogs.
-treats against: Wide range of nematodes (especially adult GI worms, lungworms) and cestode tenaii in dogs. \
-off label use in small ruminants, cats (for giardia and lungworm) and birds and reptiles
52
Albendazole (Valbazen®) a benzimidazole
* Oral suspension licensed for use in cattle
* Indications:
* Adult flukes (Fasciola hepatica)
* Adult tapeworms
* Same GI & lung adult roundworms as FBZ
* Possible teratogenic early in gestation: * don’t use within 21 days of breeding
53
Emergency Drug Release
-an authorization under food and drug relations for a new drug to be made and sold in limited quantity to canada.
* The medication will be used to treat / diagnose a serious
* The medication is not marketed in Canada;
* Documented clinical efficacy and target animal / human safety data are available for the product
* There are no comparable products available for effectively diagnosing / treating the condition
54
What products are not eligible for an EDR?
* Biologics (vaccines or antitoxins)
* Investigational drugs that are not approved
* Products for which a comparable product is currently marketed in
Canada. Note that cost and ease of use are not valid reasons for EDR
-not a way for drug companies to bypass the approval process in canada.
55
Macrocyclic lactones
* Avermectins & Milbemycins
* Produced via fermentation by
Streptomyces in soil
* Considered endectocides
* Kill both internal & external parasites
-neorotoxin for parasite by opening Cl- channel=flaccid paralysis
56
Macrocyclic Lactone Mechanism of Action
* Activates (opens) glutamate-gated Cl- channel
* Cl- entry into cell (hyperpolarization)
* Flaccid paralysis in the worm:
* pharyngeal muscles (can’t ingest nutrients)
* somatic muscles (can’t move)
* May bind with GABA (mammel) receptors at high conc. (overdose)
57
Macrocyclic Lactone Spectrum of Activity
* Effective against most nematodes & arthropods
* Some exceptions: e.g., Demodex mites, some adult filaria (heartworm)
-not good for cestodes and trematodes
58
Macrocyclic Lactone PK
-very lipophiic with high distribution to many tissues
-mostly excreted via liver
-long elimination half life, and withdrawal times.
* Milk: Not licensed for dairy cows (except moxidectin and one formulation of eprinomectin)
59
Eprinomectin
Eprinex® Pour-On:
* Licensed for use in dairy cattle with no milk
withholding time
* Eprinomectin has Maximum Residue Limit (MRL) in milk, dont use in goats
* Unlike ivermectin (no MRL for milk in Canada.
-long range SC injection: long 4-5 month activity on worms, 4 month withdrawl period.
SC FORM NOT FOR USE IN DAIRY COWS
60
selamectin
Revolution® (generics Dolmectin, Evicto, Selavectine)
* Monthly topical formulation for cats & dogs.
-uses: fleas, mties, nematodes
-less affinity for p-gp than ivermectin so safer for ABC-B1
61
Moxidectin
* Quest / Quest Plus oral gel (horses)
* Moxidectin +/- praziquantel
* All kinds of nematodes +/- tapeworms
* Advantage Multi (monthly topical, dogs, cats, ferrets)
* Moxidectin + imidacloprid
* HW prevention, fleas, ear mites, GI nematodes
* ProHeart 6 (sustained release injection for dogs)
* HW prevention (6 months
62
Milbemycin
-milbemax. interceptor, sentineal, trifexis tablets
-heartworm prevention, hookworm, roundworm, tapeworm.
63
Macrocyclic Lactone Resistance
* Resistance reported in multiple parasite species
* Huge problem in sheep
* Emerging in cattle / horses
* Widely reported in cyasthostomes & small strongyles
* Resistance mechanisms:
* Induction of parasite efflux pumps (e.g., P-gp)
* Changes in Glu-gated Cl- channels
* Test for resistance parasites: Fecal egg count reduction
* Pre- and post-treatment fecal egg counts
* Resistance if not at least 95% reduction in counts
64
Pyrimidines (pyrantel)
-mechanisms" depolarize neuromuscular junction. N receptor agonists, lead to spastic paralysis.
-for nematodes
-salt paste suspension you can put tartate in solutions for drinking water. very safe
-pamoate formulation: drontal or exodus.
-tartrate formulation: pro-banminth premix for swine.
65
Emodepside
* Profender®= Emodepside and praziquantel
* Topical solution for cats
* Mechanism = “Induces intracellular signal transduction in
parasite pharynx and body wall muscle”
* flaccid paralysis
* Spectrum = Effective against rounds, hooks + tapeworms (PQ)
* Very safe, including pregnant queens
66
Praziquantel
* Anti-cestode (tapeworm adults not cysts) drug for dogs/cats, horses,
cattle, etc
-diplydium, taenai, echinococcus.
* Mechanism = ↑ increases cellular Ca++, leads to spastic paralysis
* Found in combination with many anti-nemotode drugs
(febantel, pyrantel, emodepside, macrocyclic lactones)
* Also available by itself: Droncit injectable/tablet
67
CYP/P-gp mediated Drug Interactions
* Droncit
* PZQ drug interaction: grapefruit juice (bergamottin)
* Inhibit CYP3A enzymes (intestinal and hepatic)
* Inhibit P-gp transporters
-grapefuit juice will decrease bioavaliability and decrease intestinal and hepatic absorption.
-increases the 1/2 life. decreases metabolism and excretion once absorbed.
-will increase concentration if taken with grapefruit juice.
68
Praziquantel in sheep herds
-praziquantal (droncit) used to treat collies and dogs which are around sheep so that there are no cysts in sheep meat.
-cant treat sheep
-farmers can get human pill from pharmacy for their large guardian dogs.
69
melarsomine
-immiticide (dogs only)
-kills dirofillaria immitis heartworms ADULTS
-asrenical
-IM injection in the deep Lumbar epaxial muscle
70
Closantel (FlukiverTM)
-taken orally into gut, absorbs into blood stream and then acts on worms which suck blood.
-oral suspension for sheeps and lambs
* Label indication: treatment of Haemonchus contortus
(Barber Pole worm) infection and some liver flukes.
-not a good dewormer for other worms only blood sucking.
* Not for lactating sheep
* Long (49 day) withdrawal time
-PK: decent oral bioavaliability, high protein binding, limited tissues distribution.
71
Coccidiostats & Antiprotozoal drugs
-Coccidia: primarily Isospora and Eimeria species
-Protozoal infections:
* Cryptosporidium
* Giardia
* Sarcocystis
* Toxoplasma
* Babesia
* Neospora
-Can act on various stages of coccidia life cycle:
* Extracellular stages (sporozoites, merozoites)
* Intracellular stages - stop or inhibit development
-life cycles are complex
72
coccidiostats vs coddidiocide
-Coccidiostat: arrest the development of the
parasite, but do not kill the coccidial stages
Coccidiocide: if they kill most of the coccidial
stages.
-label will have claim for either treatment, control/prevention or reduce fecal shedding.
73
coccidiosis therapy ionophores
-used for prophylaxis for coccidia in poultry. used in calves, sheep, rabbits.
-good for coccidiosis prevention, good for early stages of life cycle.
-inhibitory activity against all coccidial stages
-act by Na/K pump activation and distribution of electrolyte balance, transport metal cation into cells, osmotic
-ex. monesion (cattle)
-can have in feed which prevents coccidia
74
ionophore toxicity
-toxicity and death in mammals especially HORSES
-mechanism: disrupts Na/K atpase pump or heavy metal osmotic balance in cardiac and skeletal muscle.
-common causes of toxicity:
* Ionophore-containing feed meant for
pigs/poultry/calves is ingested by horses on the same farm
* Mistaken delivery of ionophore-containing feed
* Incorrect ionophore concentration in the feed
75
monensin indications feedlot cattle other than coccidia prevention
-Selectively kills Gram + bacteria (e.g. Strep bovis)
* Same osmotic disruption mechanism
* Results in ↑ propionate, ↓ methane production
General cattle claims:
* Improved feed efficiency in feedlot cattle, ↑ weight gain of cattle on
pasture
* Aid in reducing bloat in cattle grazing on legume pasture
* Reduction in fecal shedding of Mycobac. avium paratubeerculosis (MAP) in mature cattle in high-risk Johne’s disease herds
* ↓ incidence of rumen lactic acid production after acute CHO ingestion
(i.e., grain overload) – not on label, but some evidence available
76
monensin indications dairy
-Selectively kills Gram + bacteria (e.g. Strep bovis)
* Same osmotic disruption mechanism
* Results in ↑ propionate, ↓ methane production
Dairy-specific claims:
* As an aid in the prevention of subclinical ketosis in lactating
dairy cattle
* Reduced milk fat in lactating dairy cows
* Minimizing loss of body condition during lactation in dairy cows
* Improving feed efficiency of milk protein production in lactating dairy cows
77
Sulfonamides
* Antimicrobial – but can be used for cases of
clinical disease associated with coccidiosis TREATMENT
* Sulfa = analogue of PABA
* Interrupts synthesis of folate in bacterial & coccidia
T-wo sulfa drugs have anti-coccidial label claims:
* Sulfaquinoxaline (oral solution for poultry)
* Sulfamethazine (oral bolus or solution)
78
amprolium
-thiamine analouge, stops repro cycle of parasite
-important for prevention of coccidial disease not great for treatment (producers try to use it for treatment)
-oral solution and feed and water mixes for poultry and calves
-trade names: amprol
-selectively toxic for coccidia but if you give too much animal will suffer from thiamine deficiency = polio in cattle, treat with large dose of thamine early on.
-dose needs to be right to avoid toxicity
79
coccidiostats decoquinate (deccox)
-can add to milk replacer and help prevent coccidiosis specially in sheep/ goats.
80
toltazuril (Baycox)
-coccidiostat
-use in lambs, piglets, calves
-prevention of coccidian shedding, and clinical signs
-animals get immune response to coccidia after treatment.
-prolonged withholding time 48-70 days
-have to dose at right time before animal is exposed.
-other types: forceris- injectiable solution with iron for piglets, 70d withdrawl period in meat.
-extralabel use in puppies and kittens coccidiosis.
-ponazuil
81
Ponazuril
* Toltrazuril metabolite
* Approved as an “aid in reducing the clinical severity of Equine Protozoal
Myeloencephalitis (EPM) (possim disease fly had) in souther states.
caused by Sarcocystis neurona in horses”
* Oral paste in dial-a-dose syringe
* Administered daily for 28 days
* Expensive!! ($250 per multi-dose tube)
82
clindamycin for protozoa
* Lincosamide (macrolide) category of antimicrobials
* Antirobe® orals drops or capsules, generic versions
* Wide variety of antibacterial label claims
-extrabelel use: treatment of toxoplasmosis and neospora in small animals
-PK: high volume distribution
83
treatment of giargia infections
-Benzimidazoles:
* Fenbendazole
* Febantel
* Albendazole
-Metronidazole: CAN NOT USE IN ANY FOOD ANIMALS
* Flagyl® = human drug
* NEW: Eradia oral suspension
* For the treatment of Giardia in dogs
84
veterinary pesticide organophophates
-Acetylcholinesterase Inhibitors (AChEi), irreversible binding to AchE
-highly toxic to mammals, M>N. leads to skeletal paralysis at high dose.
-SLUD poisining
salivation, activation, urination,
-ach doesn't break down. accumulates.
-environmental concerns
-diazinon ear tags (control horn and face flies in cattle)
85
Carbamates as pesticides
-Acetylcholinesterase Inhibitors (AChEi)
-comeptitive inhibitor of AChE (reversible)
-less toxic to mammals than organophosphates
-used as: carbaryl dusting powder control for mites, lice, ticks, flies.
86
Pyrethrins / Pyrethroids
-pesticides
-pyrethrins are from plants, pyrethroids are synthetic
-highly lipid soluble, topical solution stay in stratum corneum so now systemic absorption.
-act on Na+ channels (stuck open)
-shampoos, sprays, dips
-act on fleas, ticks, lice, mites
-TOXIC IN CATS, due to grooming
-eg. cyfluthrin, permethrin
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Neonicotinoids as pesticides
-like nicotine but more stable
-non-ionized at pH, crosses BBB
-mechanism: activates insect nicotinic receptors. no effect on vertebrate receptors.
-depolarize so Na channels open. then stops transmission
-eg. IMIDACLOPRID, nitepryram
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IMIDACLOPRID pesticide
-neonicotinoid
-activates insect nicotinic receptors
-topical formulation for dogs and cats, minimal transdermal absorption but all over skin translocation.
-kill adult and larval fleas and lice, environment will still be contaminated need to disinfect.
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Nitenpyram (Capstar) pesticide
-neonicotinoids
* Oral tablet (DIN) flea adulticide in dogs & cats
-have to give daily so not used much.
* Administered daily if fleas observed on animal
* 100% oral bioavailability
* Effective against fipronil-resistant fleas
* Generally very safe
90
Insect Growth Regulators
* Analogues of hormones
which regulate insect
larval development
* No effect on adult
insect
-arrest development in larvae stage
-little toxicity to mammels
-eg. methoprene, pyriproxifen
91
Insect Development Inhibitors
* Block development of insect exoskeleton by
inhibiting chitin synthesis or utilisation
* Used to control fleas at the egg & larval stages.
-eg. LuFEnuron (program or sentinel)
92
LuFEnuron pesticide
-insect development inhibitor
-fleas at egg and larval stages
eg. * Program® for cats: Monthly oral suspension
* SC injection (6 mo duration)
* Sentinel® tablets for dogs (with milbemycin)
* Use in aquaculture (salmon smolts) for prevention of
sea lice
93
Isoxazoline (“Laner”)
Ectoparasiticides
-Antagonists of GABA- and glut-gated Cl- channels
* Lack of hyperpolarization = excess neural activity
* Opposite effect of macrocyclic lactones
* Effective for control of fleas and ticks (+/- mites??
-classified as drug DIN
94
different isooxazolines
as ectoparasiticides oral
* Fluralaner (tablets) ticks and fleas
-Afoxolaner (monthly tablets) ticks and fleas and burrowing mites
* Sarolaner (monthly tablets) ticks and fleas and nematode and HW prevention
* Lotilaner (monthly tablet) ticks and fleas, Hw prev, nematodes
95
isoxazoline topical vs oral
-topical isoazolines on animals can get into environment onto bedding, children, ect.
-application site needs to be dry before cudding ect animal
-oral are systemically absorbed.
96
different isooxazolines
as ectoparasiticides topical
* Fluralaner, bravecto, apply every 3 months. Vitrecto = fluralaner + moxidectin
* Topical solution for cats, apply every 2 months
* Ticks & fleas PLUS nematodes & HW prevention
- Sarolaner = Revolution PLUS (w/ selamectin) ticks
* (Es)afoxalaner = Nexgard Combo (w/ eprinomectin &
praziquantel) ticks, fleas, for cats
