Question 1

Benzimidazoles (group) BZ

Accepted Answer

``` eg Thiabendazole and fenbendazole Act against cellular integrity Inhibitors of tubulin polymerisation Bind beta-tubulin at growing end - prevent elongation Deplete energy reserves Inhibit excretion of waste Slow starvation Slow release boluses or prodrugs Poorly soluble in water and given orally ```

Question 2

Thiabendazole

Accepted Answer

A benzimidazole Act against cellular integrity Inhibitors of tubulin polymerisation Slow

Question 3

Fenbendazole

Accepted Answer

``` A benzimidazole Act against cellular integrity Inhibitors of tubulin polymerisation Febantel hydrolysed to active fenbendazole Slow ```

Question 4

Salicylanilides (group)

Accepted Answer

eg Closantel
Act against cellular integrity
Uncoupler of oxidative phosphorylation
Cause fall in tegument pH in liver fluke
Lipophilic H+ moiety allows to act as protonophores
Bind plasma proteins - ingested by blood sucking helminths
Lipophilic - can cross biological membranes
Similar effects on mammalian mitochondria
Slow

Question 5

Clorsulon

Accepted Answer

Act against cellular integrity Inhibit enzymes in glycolytic pathway Inhibits phosphoglycerate kinase and mutase Binds plasma proteins - blood ingesting helminths Slow

Question 6

Praziquantel

Accepted Answer

``` Act against cellular integrity Tegument disruption and vacuolisation Ca2+ permeabilisers - cause Ca influx Spastic paralysis Slow ```

Question 7

Proteinases

Accepted Answer

Act against cellular integrity Tegument disruption Maybe Ca2+ permeabilisers Slow

Question 8

Organophosphates

Accepted Answer

Affect NM coordination
Cholinesterase inhibitors
Phosphorylate active site serine residue
Alkaline secretions of host GI tract hydrolyze and inhibit them
Fast and irreversible
Pralidoxime chloride antidote - reactivates AChEs by cleaving phosphate ester bond

Question 9

Imidazothiazoles (group)

Accepted Answer

``` eg levamisole Affect NM coordination Cholinergic agonist Depolarisation, muscle contraction, spastic paralysis, rapid expulsion GI helminths and lungworms ```

Question 10

Levamisole

Accepted Answer

``` An imidazothiazole Affect NM coordination Cholinergic agonist Depolarisation, muscle contraction, spastic paralysis, rapid expulsion GI helminths and lungworms Water solube ```

Question 11

Tetrahydropyrimides (group)

Accepted Answer

``` eg pyrantel Affect NM coordination Cholinergic agonist Depolarisation, muscle contraction, spastic paralysis, rapid expulsion GI helminths and lungworms ```

Question 12

Pyrantel

Accepted Answer

``` A tetrahydropyrimide Affect NM coordination Cholinergic agonist Depolarisation, muscle contraction, spastic paralysis, rapid expulsion GI helminths and lungworms ```

Question 13

Paraherquamide (PHQ)

Accepted Answer

``` Affect NM coordination Cholinergic antagonist Oxindole alkaloids Flaccid paralysis 1000fold more active at parasitic nACHR than mammalian ```

Question 14

Piperazine

Accepted Answer

``` Affect NM coordination Muscle hyperpolarisation GABA agonist Opens ligand gated Cl- channels Flaccid paralysis Also inhibits succinate production and depletes ATP ```

Question 15

Avermectins

Accepted Answer

-Macrocyclic lactones
Affect NM coordination
Potentiation of inhibitory transmitters
eg Ivermectin
Increase Cl- permeability -> hyperpolarisation and flaccid paralysis (of pharynx)
Glutamate gated Cl- channels - invertebrate specific

Anthelmintics Flashcards

(26 cards)