Parasiticides

Question 1

Which topical flea prevention should NOT be used on rabbits

Answer 1

Fipronil (Frontline)

DO NOT USE ON RABBITS OR HEDGEHOGS

Question 2

What agency regulates topical insecticides

Answer 2

EPA

CANNOT USE OFF-LABEL

Question 3

What agency regulates oral and transdermally absorbed insecticides

Answer 3

FDA

Question 4

How do oral insecticides reach the skin

Answer 4

Sebum

Question 5

What is the only APPROVED treatment for generalized demodicosis in dogs

Answer 5

Amitraz (mitaban)

Question 6

Which species can you NOT use organophosphates on

Answer 6

Cats

Potent cholinesterase inhibitor

Question 7

What receptor does Dinotefuran (Vectra) bind

Answer 7

Nicotinic receptors

Continuous nerve stimulation and death of insect

Question 8

What receptor does Fipronil (Frontline) bind

Answer 8

GABA receptor antagonist

Question 9

MOA amitraz

Answer 9

1) Inhibit MAO
2) Inhibit prostaglandin synthesis
3) Alpha-adrenergic agonist

Oxidized protect has increased toxicity

Question 10

AEs amitraz

Answer 10

Sedation, pruritus, hypothermia, bradycardia, hypotension

Question 11

What are the 2 general types of insect growth regulators

Answer 11

1) Juvenile hormone analogs
2) Chitin synthesis inhibitors

Question 12

Name 3 juvenoids (hormone analogs)

Answer 12

1) Methoprene
2) Fenoxycarb
3) Pyriproxyfen

Combine with an adulticide

Question 13

MOA Imidacloprid (Advantage)

Answer 13

Binds to nicotinic receptor on post-synaptic neuron –> BLOCKS signal transduction

Question 14

AE of pyrethrin, pyrethroids (permethrin) on cats

Answer 14

CNS signs

Question 15

Effects of Sulfur

Answer 15

• Fungicidal, Bactericidal, Keratolytic, Antipruritic.
• Effective for non-follicular mites
• Safe for dogs, cats

Question 16

MOA Avermectins, milbemycins

Answer 16

Potentiate release of GABA

Agonist of glutamate-gated channels

–> PARALYSIS

Question 17

Why are avermectins usually safe in mammals, but cause paralysis in insects

Answer 17

GABA is peripheral in insects, but only in CNS in mammals

These drugs don’t cross BBB, so safe (except ABCB1 mutants!)

Question 18

What is the mutation in p-glycoprotein gene of Collies, Shelties, Aussies– caution with ivermectin

Answer 18

Nt230 (del4)

Gene is ABCB1 (MDR1) gene

Function: limit penetration of substances into the CNS

Question 19

Treatment for screwworm myiasis (Cochliomyia hominivorax) in cattle/swine

Answer 19

Doramectin

Question 20

What works better for GI parasites: Milbemycin or Ivermectin

Answer 20

Milbemycin

Question 21

Treatment for Hypoderma in cows

Answer 21

Moxidectin

Question 22

MOA Lufenuron

Answer 22

Chitin synthesis inhibitor

=IGR. Fleas do not hatch from eggs or develop past larvae!

Question 23

MOA Nitenpyram (Capstar)

Answer 23

Nicotinic acetylcholine receptor –> Excitability

Rapidly absorbed 100% within 3-4hr

Question 24

MOA Spinosad (Comfortis)

Answer 24

Nicotinic acetylcholine receptor –> Excitability, paralysis, death

Question 25

Which medication should NOT be combined with ivermectin

Answer 25

Spinosad (Comfortis)

Spinosad acts as a p-glycoprotein inhibitor. Increased ivermectin in CNS –> toxicity

Question 26

Signs of ivermectin toxicity

Answer 26

• Mydriasis
• Hypersalivation
• Lethargy
• Ataxia
  *Tremors
  *Coma
  *Death