pharmacology 5

Question 1

parasiticide

Answer 1

drug that kills parasites

Question 2

anthelmintic

Answer 2

drug that kills worm (helminths)

Question 3

pesticide

Answer 3

drug usually used for external parasite/arthropods (extoparasiticide)

Question 4

insecticide

Answer 4

kills insect

Question 5

acaricide

Answer 5

kills ticks and mites

Question 6

big three

Answer 6

benzimidazoles (BZD)
pro-benzimidazoles
nicotinic agonist
macrocyclic lactones (ML)

Question 7

benzimidazoles and pro-benzimidazoles

Answer 7

generic names end in “azole”
widely used in vet med
fenbendazole
albendazole
febantel
oxibendazole and oxfendazole

Question 8

benzimidazole mode of action

Answer 8

blocks assembly
bind to parasite beta tubulin
prevents microtubule assembly
interferes with cell internal structure and metabolism
causes slow parasite death

Question 9

benzimidazole-spectrum of action

Answer 9

nematodes primarily
adulticidal, larvicidal, and ovicidal activity
no effect against hypobiotic

Question 10

trematodes and cestodes

Answer 10

ruminants
adulticidal
(essentially in ruminant flukes and tapeworms)

Question 11

admin and saftey-benzimidazole

Answer 11

administration-oral only not very water soluble
saftey-very safe
exceptions:do not give albendazole to early pregnancy ruminants
do not give febantel to pregnant dogs

Question 12

benzimidazole-species

Answer 12

dogs-febantel, fenbendazole (albendazole not approved)
horses-fenbendazole
ruminants-albendazole and fenbendazole
pigs and poultry-fenbendazole

Question 13

nicotinic agoinsts

Answer 13

imidazothiazoles and levamisole
tetrahydropyrimidines and pyrantel morantel

Question 14

nicotinic mode of action

Answer 14

they act selectively as agonists at nicotinic receptors on nematodes muscle cells: depolarizing neuromuscular-blocking drug
contraction and rapid spastic paralysis of worms

Question 15

nicotinic-spectrum of action

Answer 15

GIN adults
lung worms adults and larval stage
pyrantel-dogs <2 weeks
pyrantel-double dose in horse for tape worms
pyrantel and morantel not absorbed from the gut

Question 16

administration and safety of nicotinic

Answer 16

administration orally
safety-margin of levamisole is lower than for other modern anthelmintics
signs of toxicity related to the mode of action: it works in the host cell as well: salivation, tremors, ataxia, urination and defecation

Question 17

species of nicotinic agonists

Answer 17

horses, ruminants-mostly small, dogs and cats

Question 18

macrocyclic lactones

Answer 18

milbemycins-moxidectin, milbemycin oxyme
avermectins-selamectin, ivermectin and eprinomectin

Question 19

macrocyclic lactones-mode of action

Answer 19

bind to glutamate gated chloride channels leading to hyperpolarization of nerves and muscles
multiple effects in muscles: paralysis of muscles, affects parasite reproduction
some products have persistent activity, affected by formulation and administration route

Question 20

macrocyclic lactones-spectrum of action

Answer 20

nematodes:adults, mucosal larvae and hypobiotic larvae
arthrodos: blood sucking and tissue dwelling, varies depending on product and species

Question 21

route of administration and safety for macrocyclic lactones

Answer 21

admin: oral, injection, topical and absorbed through skin
safety: general wide safety margin, mammalian toxicity probably related to GABA synapse
macrolides generally dont reach susceptible target in vertebrates CNS because of the BBB
todxicity related to CNS depression