Parasiticides Flashcards
Which topical flea prevention should NOT be used on rabbits
Fipronil (Frontline)
DO NOT USE ON RABBITS OR HEDGEHOGS
What agency regulates topical insecticides
EPA
CANNOT USE OFF-LABEL
What agency regulates oral and transdermally absorbed insecticides
FDA
How do oral insecticides reach the skin
Sebum
What is the only APPROVED treatment for generalized demodicosis in dogs
Amitraz (mitaban)
Which species can you NOT use organophosphates on
Cats
Potent cholinesterase inhibitor
What receptor does Dinotefuran (Vectra) bind
Nicotinic receptors
Continuous nerve stimulation and death of insect
What receptor does Fipronil (Frontline) bind
GABA receptor antagonist
MOA amitraz
1) Inhibit MAO
2) Inhibit prostaglandin synthesis
3) Alpha-adrenergic agonist
Oxidized protect has increased toxicity
AEs amitraz
Sedation, pruritus, hypothermia, bradycardia, hypotension
What are the 2 general types of insect growth regulators
1) Juvenile hormone analogs
2) Chitin synthesis inhibitors
Name 3 juvenoids (hormone analogs)
1) Methoprene
2) Fenoxycarb
3) Pyriproxyfen
Combine with an adulticide
MOA Imidacloprid (Advantage)
Binds to nicotinic receptor on post-synaptic neuron –> BLOCKS signal transduction
AE of pyrethrin, pyrethroids (permethrin) on cats
CNS signs
Effects of Sulfur
- Fungicidal, Bactericidal, Keratolytic, Antipruritic.
- Effective for non-follicular mites
- Safe for dogs, cats
MOA Avermectins, milbemycins
Potentiate release of GABA
Agonist of glutamate-gated channels
–> PARALYSIS
Why are avermectins usually safe in mammals, but cause paralysis in insects
GABA is peripheral in insects, but only in CNS in mammals
These drugs don’t cross BBB, so safe (except ABCB1 mutants!)
What is the mutation in p-glycoprotein gene of Collies, Shelties, Aussies– caution with ivermectin
Nt230 (del4)
Gene is ABCB1 (MDR1) gene
Function: limit penetration of substances into the CNS
Treatment for screwworm myiasis (Cochliomyia hominivorax) in cattle/swine
Doramectin
What works better for GI parasites: Milbemycin or Ivermectin
Milbemycin
Treatment for Hypoderma in cows
Moxidectin
MOA Lufenuron
Chitin synthesis inhibitor
=IGR. Fleas do not hatch from eggs or develop past larvae!
MOA Nitenpyram (Capstar)
Nicotinic acetylcholine receptor –> Excitability
Rapidly absorbed 100% within 3-4hr
MOA Spinosad (Comfortis)
Nicotinic acetylcholine receptor –> Excitability, paralysis, death
Which medication should NOT be combined with ivermectin
Spinosad (Comfortis)
Spinosad acts as a p-glycoprotein inhibitor. Increased ivermectin in CNS –> toxicity
Signs of ivermectin toxicity
- Mydriasis
- Hypersalivation
- Lethargy
- Ataxia
*Tremors
*Coma
*Death
