anthelminitcs Flashcards
properties of anthelmintics
more toxic to worm than host
taken up by worm in sufficient quantities
inhibit metabolic processes or affect receptors vital to the worm activity
various plants were used as anthelminitcs indcluding
male fern, oil of chenopodium, pumpkin seed, tobacco
sodium fluoride
toxic to pigs and animals
copper sulfate
toxic over time
pheonthiazine and thiabendazole, nicotine sulfate
x
the toxic dose was close to the
therapeutic dose
_____ in feed are being extensively investigated, some aid in control of worms as well as being nutritionally valuable
conjugated tannins
mechanisms of action of anthelmintics
interference with energy metabolism
interference with neuromuscular transmission
interference in metabolism includes
inhibition of glucose transport
inhibition of glycolysis
membrane depolarizer
interference with neuromuscular transmission includes
inhibiting breakdown of excitatory neurotransmitters
mimicking action of excitatory neurotransmitters
hyperpolarization of neurons
albendazole MOA
(benzimidazole)glucose transport- B tubulin interferance causes failur of the cytoskeleton of absorptive cells to form
albendazole effects
flukes, tapeworms, nematodes, protozoa; used in humans and ruminants
albendazole adverse events/contraindications
teratogenic, low levels of toxicity to vertebrates
fenbendazole MOA
benzimidazole
fenbendazole effect
cestodes, nematodes in cattle and horses
fenbendazole adverse effects/contraindications
low levels of toxicity to vertebrates, resistance common in horses; may increase phenobarbital concentrations
oxfendazole MOA
benzimidazole
oxfendazole effect on
cestodes, nematodes, in cattle and horses
oxfendazole adverse events/contraindications
low levels of toxicity to vertebrates, resistance common in horses; not for use in sick or debilated horses or female dairy cattle of breeding age
oxibendazole MOA
benzimidazole
oxibendazole effect
cestodes, nematodes in horses only (some use in dogs); used when there is some resistance of horses with anthelmintics
oxibendazole adverse events/contraindications
low levels of toxicity to vertebrates, resistance common in horses; vomiting and diarrhea in dogs; not for use in dogs with heartworms
febantel MOA
(probenzimidazole)
febantel effects
nematodes, cestodes in horses and dogs; used in combo with praziquantel
febantel adverse events/contraindications
low levels of toxicity to vertebrates, vomiting, diarrhea; not for pregnant animals or those with liver or kidny dysfunction
melarsamine (immiticide) MOA
(arsenical) inhibits glycolysis of adult heartworms in dogs
melarsamine effect
slowly kills HW in dogs
melarsamine adverse events/contraindications
pulmonary thromboembolism, anorexia, injection site rxn, elevated liver enzymes; use cautiously in animals with high heartworm burden; not class 4 dz
epsiprantel MOA
(isoquinolone) altered permeability to Ca affects glucose uptake, muscular contraction and integumental disruption
epsiprantel effects
cestodes in dogs and cats
epsiprantel adverse events/contraindications
vomiting/anorexia/diarrhea
not for animals younger than 7 weeks
praziquantel moa
isoquinolone
praziquantel effect
cestodes and trematodes in dogs, cats, horses, and people
praziquantel adverse events/contraindications
vomiting/diarrhea/anorexia/ not for cats younger than 6 weeks, or dogs younger than 4 weeks
dichlorvos MOA
(organophosphate) acetycholinesterase inhibitor causing spastic paralaysis
dichlorvos effect
intestinal trematode in swine and horses
dichlorvos adverse events/contraindications
danger of toxicity if administered with other pesticides, overdose signs include SLUD;
not for Pt with HW
piperazine MOA
(heterocyclic compound) affects muscle membrane chloride channels to hyperpolarize the neuromuscular junction membranes; flaccid paralysis;
piperazine adverse effects
safe but can cause ataxia, muscle tremors, changes in behavior
levamisole MOA
(imidothiazole) mimics excitatory neurotransmitters (nicotinic agonists) hyperpolarizes muscles causing spastic paralysis
levamisole adverse events/contraindications
cholinergic toxicity, vomiting, swelling when injected, immunostimulant in people-may also be converted into CNS stimulants; use caution in animals with high microfilaria
pyrantel MOA
(tetrahydropyrimidine) mimics excitatory neurotransmitters )nicotinic agonists) hyperpolarizes muscles causing spastic paralysis
morantel moa
tetrahydopyrimidine
levamisole effect
only actively feeding nematodes in ruminants and swine
pyrantel effect
nematodes and tapeworms at high doses in dogs cats, horses, humans, and swine
morantel adverse events
cross resistance with levamisole
morantel use (legal)
can be used in dairy cattle without milk withdrawal; 2-4 weeks for meat
emodesepside MOA
(cyclooctadespeptide); binds to presynaptic receptors cause flaccced paralysis; altered pharyngeal function and worm motility
enidesepside effect
GI nematodes in cats
morantel effects
nematodes in ruminants
toluene dichlorophene MOA
altered permeability to Ca affects glucose uptake, muscular contraction and tegumental disruption
toluene dichlorophene adverse events
poorly effective; narrow safety margin
ivermectin MOA
(macrolytic lactones) increased release of inhibitory neurotransmitters lead to flaccid paralysis; affects glutamate gated chloride channels
ivermectin effect
adult and larval nematodes and arthropods in mammals and birds
ivermectin adverse events/contraindications
toxicity may occur in breeds with MDR gene mutation; not for animals younger than 6 weeks; drug excreted in milk
doramectin MOA
macrolytic lactone
doramectin effect
nematodes and external parasites in cattle and swine; lung worm, scabies, notoedric mange
doramectin adverse events
WDR mutant breeds susceptible; only approved in cattle; dont use with drugs that inhibit p glycoprotien
eprinomectin MOA
MACROCYCLIC LACTONE
eprinomectin effects
nematodes and external parasites in cattle
eprinomectin adverse events
WDR gene susceptible; blood levels remain high for 140 days
milbemycin MOA
macrocyclic lactone
milbemycin effect
hear worms; ginematodes, ascarids in dogs and cats;
milbemycin adverse events/contraindications
MDR; not for young animals; transmitted in milk; p glycoprotein inhibitors
moxidectin MOA
macrocyclic lactone
moxidectin effect
nemotodes and ectoparasites in horse, cattle, sheep, dogs
moxidectin adverse events/contraindications
can cross bbb in malnourished animals; leghargy; decreased appetate; lesion at injection site; sedation, weakness, bradycardia, dyspnea, seizures, coma
selamectin (revolution) MOA
macrocyclic lactone
selamectin effect
hearworm, arthropods, and GI nemotodes (hooks in dogs, hooks and rounds in cats)
selamectin adverse events/contraindications
mdr mutant breeds; transient alopecia at site of application, nausea, lethargy, salivation, tachypnea, tremors, not for dogs less than 6 weeks and cats less than 8 weeks