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124 Cards in this Set

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Griseofulvin

a. spectrum
b. mechanism of action
c. route of administration
a. dermatophytes
b. incorporates into keratin of affected skin & nails
- binds to microtubules --> compromises spindles & inhibits mitosis of fungal cells (fungistatic)
c. oral
Griseofulvin

a. duration of tx required
b. adverse effects
a. > 4 wks
b.
-BM suppression, esp. in cats w/ viral infection (ex. FeLV)
-cats: teratogenic: cranial & skeletal malformations, ocular, intestinal, cardiac problems
-horses: teratogenic in early pregnancy (~ 2 mo)
Amphotericin B

a. spectrum
b. mechanism of action
c. route of administration
a. used to tx systemic fungal infections
b.
-binds to sterols in fungal cell mem --> cell mem becomes more permeable --> fungal cell death (fungicidal)
-can also bind to cholesterol in mammalian cells --> toxicity
c. IV
Amphotericin B

c. adverse effects
d. strategies to decrease toxicity
c. fever, thrombophlebitis, nausea, vomiting, anorexia, renal injury (acute or chronic (cumulative))
d.
-pre-treatment fluid administration
-slow IV infusion over 60 min
-SQ administration
-liposomal/intralipid formulations
Azole antifungal drugs

a. mechanism of action
b. members of class
a. inhibits fungal cell P-450 enzyme response for synthesis of fungal cell sterols (ergosterol)
-fungistatic
b. Ketoconazole, Miconazole, Clotrimazole, Enilconazole
Ketoconazole

a. spectrum
b. route of administration
c. pharmacokinetics
a. yeasts (Malassezia pachydermatis), dermatophytes, systemic fungi (Blastomyces, Coccidiodes, Histoplasma)
b. oral
c.
-oral absorption enhanced by food
-pH dependent solubility: inhibited by stomach antacids
-poorly absorbed in horses
Ketoconazole

a. duration of tx required
b. adverse effects
c. drug interactions
a. 4 wks to several months
b.
-nausea, vomiting, diarrhea, cataracts, fetal death
-hepatotoxicosis: idiosyncratic (more likely at higher doses)
-inhibits steroid synthesis: CYP450 mediated
-↓ testosterone & cortisol: used for short term management of Cushing’s
c.
-inhibits CYP450 enzymes --> inhibits metabolism of some drugs
-cyclosporine: used clinically to ↓ dose/cost of CsA tx
-prednisolone (but not prednisone --> prednisolone)
-digoxin, warfarin

-inhibits p-glycoprotein efflux pumps: may lead to ↑ concentrations of substrates in CNS, eye, plasma
Miconazole

a. route of administration
b. clinical use
a. topical
b. solution for ocular use, cream or lotion for tx of dermatophytes
Clotrimazole

a. route of administration
b. clinical use
a. topical
b.
-solution for tx of nasal aspergilosis & fungal cystitis
-combined w/ gentamicin & betamethasone in Otomax
Enilconazole

a. route of administration
b. clinical use
a. topical
b. tx of dermatophytes, local infusion for nasal aspergillosis
Triazoles

a. differences from azoles
b. members of class
a. better tolerated than ketoconazole, less inhibition of CYP450 enzymes, no endocrine effects
b. Itraconazole, Fluconazole, Voriconazole
Itraconazole

a. spectrum
b. pharmacokinetics
a. dermatophytes, yeasts (Malassezia, Candida), systemic fungi (Blastomyces, Coccidiodes, Histoplasma, Aspergillus)
b.
-absorption of capsules ↑ by food in dogs & cats
-↓ absorption in horses: not practical to use (expensive, large volume of solution required)
-highly lipophilic: concentrates in tissues for 2-4 wks
Itraconazole

a. adverse effects
b. drug interactions
a.
-hepatic: ↑ liver enzymes (10-43%), hepatotoxicosis (10%)
-GI: anorexia, vomiting (2-3%)
-CHF: check for underlying cardiac dz
b. will ↑ blood levels of CsA, digoxin, but to a lesser extent than Ketoconazole
What is the tx of choice for Blastomyces or Histoplasma?
Itraconazole
Fluconazole

a. spectrum
b. differences from other Azoles
a. dermatophytes, yeasts (Malassezia, Candida), systemic fungi (Blastomyces, Coccidiodes, Histoplasma)
b.
-water soluble
-higher concentrations in urine, CSF, aqueous humor
-high oral absorption, even in horses: not affected by antacids, feed, or formulation
-low protein binding
-little effect on CYP450 or p-glycoprotein
What is the tx of choice for Cryptococcus in dogs & cats?
Fluconazole
Voriconazole

a. spectrum
b. differences from other Azoles
a. dermatophytes, yeasts (Malassezia, Candida), systemic fungi (Blastomyces, Coccidiodes, Histoplasma, Aspergillus), Fusarium
b.
-more water soluble than itraconazole & ketoconazole
-more lipophilic than fluconazole
-intermediate protein binding
-excellent oral absorption (~100%)
-excellent penetration of CNS & eye
-autoinduction of metabolizing enzymes has been demonstrated in dogs, birds, lab animals
Terbinafine

a. spectrum
b. mechanism of action
c. brand name
a. Dermatophytes, Malessezia, Blastomyces, Histoplasma, Cryptococcus, Sporothrix, protozoa (Toxoplasma): fungicidal
b. inhibits ergosterol synthesis thru inhibition of squalene epoxidase
c. Lamisil
Terbinafine

a. adverse effects
b. clinical use
a. dogs: mild-moderate ↑ hepatic enzymes

b. tx of dermatophytes in dogs & cats (accumulates in hair & skin)
Lufenuron

a. brand name
b. mechanism of action
c. clinical uses
a. Program
b. inhibits chitin synthesis
c.
-dogs & cats: tx of fleas & dermatophytes
-horses: fungal endometritis (uterine infusion)
steps to minimize anticancer drug toxicity
-use combination drugs so smaller doses of individual drugs can be used
-monitor for toxicity (CBC, renal function, cardiac function)
-administer fluid therapy prior to nephrotoxic drugs
-administer anti-emetic drugs when nausea or vomiting is anticipated
-dose selection: surface area vs. body weight (controversial)
alkylating agents

a. mechanism of action
b. example
a.
-alkylate bases of DNA - cross-links bases of DNA --> cessation of DNA synthesis --> cell death
-bifunctional alkylating agents: cross link double stranded DNA (binds to both sides)
-more active on growing cells than dormant cells but are non-cycle specific
b. Cyclophosphamide
Cyclophosphamide

a. clinical uses
b. metabolism
c. specific class
a. LSA, carcinomas, immunosuppressive therapy (pemphigus vulgaris, IMHA, systemic lupus): can be given orally
b.
-must be metabolized to active metabolites for pharmacologic effect (requires CYP450)
-metabolites are cytotoxic: hydroxyphosphamide, aldophosphamide
-aldophosphamide --> phosphoramide mustard (alkylating component: anticancer effects) + acrolein (cytotoxic action)
c. nitrogen mustard (alkylating agent)
Cyclophosphamide

a. adverse effects
-bone marrow: dose dependent suppression
*granulocytes most severely affected --> neutropenia
*stem cells usually spared
*&nadir of toxicity: 7-10 d., w/ recovery (dogs) in 21-28 d.
-GI tract: nausea, vomiting, diarrhea
-urinary bladder: sterile hemorrhagic cystitis
*direct injury to bladder epithelium by cytotoxic metabolites (acrolein)
*dogs > cats
*methods to ↓ toxicity
-corticosteroids to induce PU/PD & ↓ bladder inflammation
-Furosemide to produce more dilute urine
-Mesna to bind metabolites in urine
-alopecia: primarily in dogs w/ continuously growing hair
Vinca Alkaloids

a. mechanism of action
b. example
a. “spindle poisons”
bind to tubulin proteins which form microtubules responsible for chromosome migration during mitosis --> block polymerization of microtubles --> arrest mitosis in metaphase
b. Vincristine
Vincristine

a. clinical uses
b. adverse effects
c. effects on platelets
a. transmissible venereal tumors (TVT), combination therapy for LSA, mammary neoplasia in cats, etc. (given IV)
b.
-local vesicant action: severe local chemical irritation resulting from perivascular leakage --> sloughed tissue
-peripheral neuropathy: related to its ability to bind tubulin, which interferes w/ axonal function
-constipation
-causes very little myelosuppression compared to other anticancer agents
c.
-ability to ↑ release of health, functional platelets from BM --> used to tx IMTP
-affinity for tubulin of platelets --> change in morphology of platelets --> ↑ release from megakaryocytes
-may also ↓ platelet destruction by inhibiting phagocytosis
Doxorubicin

a. mechanism of action
b. class
c. clinical uses
a.
-inhibits topoisomerase-II dependent DNA synthesis
intercalates b’twn DNA base pairs --> cell death by blocking RNA & protein synthesis
-other proposed mechanisms: binds to cell mems & alters ion transport, generates oxygen free radicals (toxic to cancer cells)
b. Anthracycline ABs (most widely used anticancer drugs)
c. LSA, OSA, carcinomas, sarcomas (given IV, usually every 21 d.)
Doxorubicin - adverse effects
-bone marrow suppression: nadir at 7-10 d., recovery in 21-28 d. after IV dose
-cardiotoxicity: dose-limiting toxic effect
*acute: arrhythmias during drug administration
*chronic: CM & CHF in dogs
*mechanism of toxicity: drug forms intracellular complex w/ Fe --> formation of oxygen free radicals that damage myocardial cells
*Dexrazoxane: potent chelator of Fe that may be used to ↓ toxicity
-alopecia
-GI: anorexia, vomiting, diarrhea
-hypersensitivity reactions: not life-threatening, but occur commonly (pre-tx w/ antihistamines)
Effects of glucocorticoids utilized in cancer therapy
cytotoxic to malignant lymphocytes
anti-emetic (dexamethasone)
↓ inflammation assoc. w/ cancer
↓ TNF synthesis
improves appetite
factors that influence drug levels in ocular tissues
-barriers to drug penetration: corneal permeability barrier, blood/aqueous, blood/retinal, blood/vitreous barrier
-drug formulation: solubility, pH, MW
-freq. of administration: usually 3-4x daily
-route of administration
-location of dz process
How does the corneal permeability barrier affect drug penetration?
-corneal epi composed of both hydrophobic cells (surface epi) & hydrophilic cells (stroma)
-drugs capable of existing in a biphasic state penetrate cornea most efficiently
How do the blood/aqueous, blood/retinal, blood/vitreous barriers affect drug penetration?
smaller MW, lipid soluble drugs penetrate barrier most readily

w/ intraocular inflammation, barriers are disrupted & many drugs are capable of entering ocular tissues & reaching therapeutic levels
When are systemic drugs used in ocular pharmacology?
used for prophylaxis or tx of all intraocular microbial infections (topical ABs do NOT reach therapeutic levels in eye)

systemic anti-inflammatories used for moderate to severe intraocular inflammatory dz

unnecessary & not useful for surface dz
What type of therapy is indicated for dz in:

a. adnexa
b. cornea
c. intraocular: anterior seg.
d. intraocular: posterior seg.
e. retrobulbar
a. generally topical therapy indicated, w/ addition of systemic therapy if eyelids or nasolacrimal system involved
b. topical therapy (if not a penetrating lesion)
c. topical &/or systemic therapy
d. systemic therapy
e. systemic therapy
aqueous humor

a. where secreted
b. function
c. conventional outflow
d. unconventional outflow
a. by ciliary body
b. provides nutrients to avascular lens & cornea
c. thru trabecular meshwork at iridocorneal angle & thru scleral venous plexus
d. thru ciliary m. & out thru sclera (horse: 60-70%)
What is always the underlying cause of increased IOP in glaucoma?
↓ in outflow facility
What is primary glaucoma & what are the 3 types?
primary alteration in iridocorneal angle structures or physiologic processes (usually genetic in dogs, rare in other species)

1. narrow (closed) angle: iridocorneal angle is narrowed or closed (most common type of primary glaucoma in dogs)
2. pectinate ligament dysplasia (goniodysgenesis): occurs 2º to abnormal development of iridocorneal angle
3. open angle: iridocorneal angle appears open, & obstruction to outflow is in trabecular meshwork or scleral venous plexus (rare in dogs)
What is secondary glaucoma & what are some common causes?
results from another dz process (can be open angle or closed angle)

causes: inflammation (uveitis), changes in lens size or position, intraocular neoplasia
What is the goal of drugs used to tx glaucoma?
↑ outflow of aqueous humor
What are 5 classes of drugs used to tx glaucoma?
beta blockers
carbonic anhydrase inhibitors
osmotherapeutic agents
prostanoids
parasympathomimetic agents
beta blockers for tx of glaucoma

a. mechanism
b. preparations used
a. ↓ IOP by ↓ secretion of aqueous humor (exact mechanism unknown)
b. timolol (non-selective B antagonist), betaxolol (B-1 antagonist)
carbonic anhydrase inhibitors for tx of glaucoma

a. mechanism
b. clinical uses
c. preparations
a. ↓ aqueous humor production by inhibiting catalytic conversion of CO2 to HCO3- (bicarb)
b. -can be synergistic w/ β-blockers
-very effective in glaucomas 2º to inflammation or tumors
c. Dorzolamide hydrochloride (topical)
osmotherapeutic agents for tx of glaucoma

a. mechanism
b. clinical uses
c. preparations
a. ↓ IOP by making serum hyperosmotic to intraocular fluids --> fluids drawn out of eye
b. -effective in short term tx of ↑ IOP (esp. acute congestive glaucoma in dogs)
-less useful in initial management of some 2º glaucomas, as an intact blood ocular barrier is required for them to exert their osmotic effect
c. oral: glycerol, IV: mannitol
prostanoids for tx of glaucoma

a. mechanism
b. preparations
a. ↓ IOP by ↑ uveoscleral outflow (dogs > horses > cats)
b. Latanoprost: PGF2-alpha

do NOT use to tx glaucoma 2º to uveitis
parasympathomimetic agents for tx of glaucoma

a. mechanism
b. effects in horses
c. preparations
a. cause miosis --> pulls iris out of angle & opens meshwork --> more efficient fluid flow
b. cause ↑ IOP: contracture of ciliary mm. --> ↓ room for fluid to flow (horses have 70% uveoscleral outflow)
c. pilocarpine

NOT widely used now
3 uses of medical therapy in tx of glaucoma in dogs
1. treating acute congestive glaucoma (IOP > 50 mm Hg) in which you need to ↓ IOP quickly to lessen damage to retina & optic nerve

2. often necessary as adjunct to surgical therapy

3. as prophylaxis in fellow eye of a dog that glaucoma in 1 eye
emergency therapy for acute congestive glaucoma
topical latanoprost, IV mannitol, topical CAI
maintenance therapy for dogs w/ glaucoma
topical CAI, + timolol if needed, + latanoprost as a “rescue agent”
tx of secondary glaucoma
usually managed w/ anti-inflammatory therapy, sometimes add glaucoma meds
majors uses of mydriatics
-diagnostic procedures: to dilate pupil & examine fundus

-tx of anterior uveitis: to block painful ciliary body & iris spasm

-before certain types of intraocular sx: cataract sx to dilate pupil
What do cycloplegic drugs do?
paralyze ciliary muscle
What 2 classes of drugs are used as mydriatics?
sympathomimetics (adrenergic agonists): NOT commonly used (phenylephrine, epi)

parasympatholytics (cholinergic antagonists)
parasympatholytics used as mydriatics & cycloplegics

a. mechanism
b. 2 commonly used preparations
a. block action of Ach on iris sphincter & ciliary mm.

b.
atropine (duration: 4-5 d): used for therapeutic purposes to tx painful eyes

tropicamide (duration: 4-5 hrs): used for diagnostic purposes
corticosteroids used to tx ocular inflammation

a. preferred formulation
b. indications for use
c. contraindication for use
a. prednisolone acetate: preferred formulation for tx of intraocular inflammation d/t high degree of corneal penetration
b. -topical corticosteroids indicated for tx of ocular surface & anterior segment inflammatory dz
-systemic corticosteroids indicated for moderate to severe anterior segment inflammatory dz & all posterior segment or retrobulbar inflammation
c. presence of corneal ulceration: steroid inhibits tear film immune fn & predisposes to microbial infection & inhibits corneal wound healing
NSAIDs for tx of ocular inflammation

a. clinical uses of topical NSAIDs
b. clinical uses of systemic NSAIDs
a. Flurbiprofen (Ocufen), Suprofen (Profenal)
-used prior to cataract sx as aid to mydriasis
-used as adjunct to topical steroids for tx of intraocular inflammation or as an alternative when topical steroids are contraindicated
b. aspirin, flunxin, indomethacin
-sometimes used prior to cataract sx, to tx uveitis when steroids are contraindicated
uses of topical antibiotics for tx of the eye
-surface bacterial infection
-prophylaxis when surface integrity of conjunctiva or cornea is disrupted (ex. corneal ulcer)
What is the 1st line ocular AB used in dogs & horses & why is it not 1st line in cats?
triple antibiotic

rare reports of anaphylaxis in cats: NOT 1st choice
triple AB: topical tx of eye

a. drugs it contains
b. spectrum
a. neomycin, polymyxin B, & bacitracin or gramicidin

b. broad spectrum, esp. for Gram positive: useful to tx or prevent infection by Gram positive cocci
What are the spectrum/uses of the following topical antibiotics to tx the eye?

a. gentamicin
b. Ciprofloxacin
c. Tobramycin
a. broad spectrum, useful if rods (Gram negative infection) are present
b. broad spectrum: reserve for known active infection
c. resistant Pseudomonas infection
What antiobiotic is the tx of choice for CATS w/ conjunctivitis or as prophylaxis in cats w/ feline herpes virus conjunctivitis?
tetracycline or oxytetracycline

effective against Chlamydia & Mycoplasma
What is the only common indication for use of antivirals in ocular pharm?
feline herpetic keratoconjunctivitis
ocular antivirals

a. mechanism of action
b. what drug has best in vitro activity against feline herpes virus 1?
a. interfere w/ viral DNA or RNA synthesis
b. Trifluoridine
oral l-lysine

a. mechanism
b. pros
c. clinical use
a. competitively interferes w/ arginine incorporation into viral DNA
b. inexpensive, benign therapy, but efficacy not well documented
c. FHV-1 keratoconjunctivitis
tx of FHV-1 conjunctivitis
prophylactic topical tetracycline, oral L-lysine if chronic
tx of FHV-1 keratitis
prophylactic topical tetracycline, topical antiviral, +/- topical atropine, +/- oral L-lysine
What is the most common use of antifungals in ocular pharm?
fungal keratitis: common in horses

risk factors: trauma from plant material, prior topical steroid/AB use (normal fungal flora proliferate)

etiology: Aspergillus, Fusarium
antifungals in ocular pharm

a. only approved ophthalmic antifungal
b. other antifungals that may be used
a. Natamycin
b. Miconazole, Vorinconizole (topical)
Fluconazole: can reach therapeutic levels in cornea following oral administration, can be used as adjunct to topical antifungal tx (expensive)
What is the main use of lacrimometic & lacrimogenic agents?
tx aqueous tear deficiency or keratoconjunctivitis sicca (KCS)
-common 1º (genetically influenced) dz in dogs: degeneration of lacrimal glands
lacrimometic agents

a. what they do
b. examples
a. mimic tear film
b. artificial tears, ophthalmic lubricating ointments, collyria (eye washes)
lacrimogenic agents

a. what they do
b. examples
a. stimulate tear film
b. pilocarpine, cyclosporine A, tacrolimus
local anesthetics used for tx of eye

a. clinical uses
b. contraindication
c. preparation commonly used
a. routine diagnostic & minor surgical procedures (lasts ~20 minutes)
b. for tx of corneal ulcers or other painful eye conditions: inhibit corneal wound healing & normal blink reflex
c. 0.5% proparacaine
heterocyclic compounds

a. mechanism of action
b. 2 examples
c. class of parasite treated
a. block action of Ach at NM junction OR by stimulating GABA receptors --> hyperpolarization of nerve endings --> flaccid paralysis of worm
-mature worms more susceptible than larval stages

b. piperazine, diethylcarbamazine citrate (Filarbits)
c. nematodes
piperazine

a. class
b. spectrum in dogs & cats
c. spectrum in horses
d. spectrum in swine
e. spectrum in ruminants
f. why shouldn't you use in animals w/ high ascarid load?
a. heterocyclic compound
b. ascarids
c. ascarids, some strongyles, pinworms
d. ascarids, nodular worms (used extensively in feed or water)
e. NOT approved
f. provides a fast kill: risk of impaction colic or perforation of SI
benzimidazoles

a. mechanism of action
b. classes of parasites treated
c. adverse effects
a. bind to nematode dimeric tubulin --> prevents polymerization of tubulin during microtubule assembly
b. nematodes, cestodes, trematodes, protozoa
c. -albendazole contraindicated in cattle & sheep during pregnancy
-drugs are generally persistent, requiring a withdrawal time
benzimidazoles: spectrum in:

a. horses
b. cattle & sheep
c. swine
d. dogs
a. Fenbendazole: small & large strongyles, pinworms
b.
-Fenbendazole: effective against larval & adult stages of major GI nematode
-Albendazole & Fenbendazole: tissue stages of Ostertagia; lungworms
c. -Fenbendazole: kidney worms, lungworms, nodular worms, whipworms
-Mebendazole: muscular L1 stage of Trichinella spiralis
d. Mebendazole: hookworms, ascarids, whipworms, tapeworms
-Fenbendazole only approved for dogs, NOT CATS
probenzimidazoles

a. example
b. spectrum in horses
c. spectrum in dogs
a. Febantel (pro-drug w/ no anthelminthic activity until metabolized)
b. adult strongyles, ascarids, pinworms
c. formulated w/ praziquantel & pyrantel pamoate (Drontal Plus)
-hookworms, ascarids, whipworms, tapeworms
-not as well tolerated in cats as in dogs
Levamisole

a. class
b. mechanism of action
c. spectrum in cattle & sheep
d. spectrum in swine
e. toxicity
a. imidazothiazole
b. cholinomimetic: acts as a ganglionic stimulant --> paralysis of worms caused by depolarizing NM blockade or sustained muscle contraction
c. abomasal, intenstinal worms, VERY good for lungworms
d. ascarids, lungworms, nodular worms, kidney worms
e. narrow margin of safety --> may see effects similar to organophosphate poisoning
-NOT A DRUG OF CHOICE, except perhaps for lungworms
-do NOT give w/ organophosphates: synergistic!
pyrantel salts

a. mechanism of action
b. 2 subtypes
c. spectrum in horses
d. spectrum in swine
e. spectrum in ruminants
f. spectrum in dogs & cats
g. toxicity
a. nicotinic agonist --> muscular contraction & tonic paralysis
b. tartate salt, pamoate salt
c. Strongylus vulgaris, ascarids, pinworms
d. ascarids, nodular worms, stomach worms
e. NOT APPROVED
f. hookworms, ascarids
g. avoid simultaneous use w/ Levamisole or organophosphates
morantel salts

a. spectrum in cattle & goats
b. milk withdrawal time
a. stomach & intestinal worms in cattle & goats
b. none
organophosphates

a. mechanism of action
b. toxicity
c. parasite classes treated
a. irreversibly inhibit AChE --> accumulation of Ach at cholinergic receptors
b. very low margin of safety; milk residue concerns
c. nematodes, ectoparasites

NEVER USE IN CATS
Dichlorvos

a. class
b. spectrum in dogs
c. spectrum in swine
d. spectrum in ruminants
a. OP
b. hookworms, ascarids, whipworms
c. ascarids, nodular worms, whipworms
d. NOT APPROVED
Coumaphos

a. class
b. clinical use
a. OP
b. approved for use in lactating dairy cattle as feed additive
Trichlorfon

a. class
b. spectrum in horses
c. spectrum in dogs
a. OP
b. ascarids, pinworms, bots (sessile & migratory)
c. ascarids, hookworms, whipworms, mange mites, fleas
macrolide endectocides

a. parasite classes treated
b. 2 classes
c. mechanism of action
d. toxicity
a. nematodes, ectoparasites
b. Avermectins, Milbemycins
c.potent GABA agonist --> inhibitory signals to motor neurons --> paralysis of parasite
-in mammals, GABA confined to CNS & drugs do NOT cross BBB --> no paralysis
-avermectins also target glutamate-gated Cl channels that are in close proximity to GABA-gated sites
d. wide safety margin: can use in pregnant animals
-high doses: CNS depression
-some Collies sensitive: multi-drug resistance gene; deficiency of p-glycoprotein efflux pump at BBB
Ivermectin

a. class
b. spectrum in cattle & sheep
c. spectrum in horses
d. spectrum in swine
e. spectrum in dogs
f. withdrawal times
g. metabolism
a. macrolide endectocide
b. all major GI worms (incl. Ostertagia L4) & lungworms
c. bots, stomach worms, small & large strongyles (incl. migrating larvae), pinworms, ascarids
d. GI worms, lungworms, kidney worms, NOT effective against Trichinella muscular stage
e. ascarids, hookworms, whipworms, heartworm preventative (larvicide), also a microfilaricide (extralabel use)
f. long
g. 90% metabolized in liver
-bile is major route of excretion: significant enterohepatic recycling
Doramectin

a. class
b. spectrum in cattle
c. spectrum in swine
d. withdrawal times
a. macrolide endectocide
b. similar to ivermectin + screw worms (drug of choice); protects against Ostertagia for 28 days
NOT APPROVED FOR DAIRY ANIMALS
c. all major GI, lung, & kidney worms, lice, mange mites
d. very long
Eprinomectin

a. class
b. spectrum in cattle
c. withdrawal times
a. macrolide endectocide
b. adult & immature helminths, lice, hornflies, mites
c. none
Selamectin

a. class
b. brand name
c. spectrum in dogs & cats
a. macrolide endectocide
b. Revolution
c. forms reservoirs in sebaceous glands --> efficacy against fleas, ear mites, sarcoptic mange mites
also HW, hooks & rounds (cats), ticks (dogs)
Milbemycin Oxime

a. class
b. brand name
c. spectrum in dogs & cats
a. macrolide endectocide
b. Interceptor
c. larvacide, HW preventative, hookworms, ascarids, whipworms, Amitraz-resistance Demodex canis, microfilaricidal (extralabel use)
Moxidectin

a. class
b. spectrum in ruminants
c. spectrum in horses
d. withdrawal times
e. former product for dogs
a. macrolide endectocide
b. similar to ivermectin + scab mite (Psoroptes ovis)
c. common internal parasites
d. none for dairy cattle
e. ProHeart 6
What is the tx of choice for screworms in cattle?
Doramectin
Melarsomine

a. class
b. brand name
c. clinical uses
d. toxicity
a. arsenical
b. Immiticide
c. drug of choice to tx heartworm infection in dogs
d. salivation, dyspnea can be reversed w/ dimercaperol
What is the drug of choice to tx heartworm infection in dogs?
Melarsomine
Praziquantel

a. brand name
b. mechanism of action
c. spectrum in dogs & cats
a. Droncit
b. related to inc. influx of Ca --> parasite muscle paralysis
c. effective against all tapeworms (cestodes)
Epsiprantel

a. spectrum in dogs & cats
a. 100% effective vs. Dipylidium caninum & Taenia pisiformis (cestodes)
What drugs are approved to tx Monezia tapeworms in ruminants?
Albendazole, Fenbendazole
Clorsulon

a. mechanism of action
b. spectrum in ruminants
c. withdrawal time
a. deprives flukes of energy source
b. 100% effective vs. adult Fasciola hepatica, higher doses needed for younger flukes (NOT APPROVED FOR DAIRY CATTLE)
c. short
What benzimidazole is effective against mature flukes?
Albendazole
Metronidazole

a. class
b. mechanism
c. clinical use
d. use in food animals
a. nitroimidazole
b. disrupts DNA synthesis
c. tx of Giardia
d. extralabel use illegal d/t suspected mutagenicity, carcinogenicity
What is the drug of choice for tx of Giardia?
Fenbendazole
Clindamycin

a. mechanism
binds to 50S ribosomal subunit --> inhibits protein synthesis
What is the drug of choice to tx Toxoplasmosis in cats & dogs?
Clindamycin
Name 4 drugs/classes effective against Coccidia.
sulfonamides
Decoquinate
Amprolium
polyether ionophores
Sulfonamides

a. mechanism
b. clinical use
a. inhibit folate synthesis
b. tx of Coccidia in ruminants, small animals
What is the drug of choice to tx Coccidia in small animals?
Sulfonamides
Decoquinate

a. mechanism
b. clinical use
c. meat withdrawal time
a. blocks DNA synthesis by inhibiting DNA gyrase
b. approved to tx coccidia in most ruminants & birds
c. none
Amprolium

a. mechanism
b. clinical use
a. competitively inhibits active transport of thiamine in Eimeria
b. only approve anticoccidial for layers
polyether ionophores

a. mechanism
b. clinical uses
c. toxicity
a. form lipophilic complexes w/ Na --> facilitates Na transport across cell mem --> inc. Na, Cl, water influx --> cell swelling, inhibition of mitonchondrial fn, ATP hydrolysis
b. anticoccidial in cattle, chickens, sheep
c. severe CV effects d/t high intracellular Ca levels (DO NOT USE in HORSES or TURKEYS)
What are 3 drugs used to tx EPM?
Ponzauril (Marquis)
Pyrimethamine + Sulfadiazine (Rebalance)
Nitazoxamide (Navigator)
What drug is used to tx canine babesiosis?
Imidocarb
What species/breeds are very sensitive to OP toxicity?
Brahman cattle
greyhounds
cats
-delayed neuropathy
carbamates

a. mechanism
b. clinical uses
a. reversible inhibit AchE --> inc. Ach at cholinergic receptors
b. in sprays, dusts, flea & tick collars for dogs & cats
pyrethrins & pyrethroids

a. mechanism
b. spectrum
c. toxicity
a. modulate Na channels --> repetitive discharge or mem. depolarization, suppress GABA & glutamate receptor-channel complexes
b. fleas, ticks, head flies
c. nerve & muscle disorders: DO NOT GIVE TO CATS!
What is the difference b'twn pyrethrins & pyrethroids?
pyrethins: plant origin
pyrethroids: synthetic (more resistant to metabolism, greater residual activity)
What ectoparasites can be treated w/ macrolide endectocides?
mites, lice, grubs
Fipronil

a. brand name
b. mechanism
c. spectrum
a. Frontline Plus: fipronil + methoprene
b. blocks passage of Cl ions thru GABA & glutamate gated channels
c. adult fleas, ticks
Imidacloprid

a. class
b. brand name
c. mechanism
d. spectrum
a. neonicotinoid
b. Advantage, K9 Advantix
c. cholinomimetic: competitive inhibition at post-synatic nicotinic sites --> disruption of nerve transmission
d. NOT effective vs. ticks
K9 Advantix (imidacloprid + pyrethrin): mosquitos, ticks, fleas (DOGS ONLY)
Nitenpyram

a. class
b. brand name
c. clinical use
a. neonicotinoid
b. CapStar
c. effective against fleas in dogs & cats
Amitraz

a. brand name
b. mechanism
c. spectrum
a. Mitaban dip
b. MAO inhibitor
c. effective against mites & ticks
Methoprene

a. class
b. mechanism
a. insect growth regulator
b. falsely signals parasite to remain immature
Lufenuron

a. class
b. mechanism
c. clinical use
a. insect growth regulator
b. inhibits chitin synthesis
c. administered orally every month to control fleas in cats & dogs
glucosamine

a. effects
a. stimulates cartilage cells to synthesize glycosaminoglycans & proteoglycans
chondroitin sulfate

a. what it is
b. effects
a. glycosaminoglycan in articular cartilage
b. stimulates repair of articular cartilage, inc. viscosity of joint fluid, inhibits enzymes that degrade articular cartilage
polysuflated glycosaminoglycans

a. brand name
b. effects
a. Adequan
b. inhibits proteases in joints, stimulates proteoglycan, collagen, & hyaluronate synthesis, improves healing of cartilage