Anthelmintics

Question 1

Albendazole

Answer 1

Benzimidazole

Inhibit microtubule polymerisation by binding to beta tubulin in parasite; other effects, eg inhibition of glucose uptake, may also contribute.

Question 2

Mebendazole

Answer 2

Benzimidazole

Inhibit microtubule polymerisation by binding to beta tubulin in parasite; other effects, eg inhibition of glucose uptake, may also contribute.

Question 3

Ivermectin

Answer 3

Alters chloride channel function by binding to glutamate-gated chloride ion channels and acting as a GABA agonist in parasite, leading to its paralysis and death.

Question 4

Praziquantel

Answer 4

At low concentrations causes increased muscular activity followed by paralysis of worms, detaching them from host tissue.

At higher concentrations causes integumental damage, which activates host defences to destroy worms (other biochemical changes also occur).

Question 5

Pyrantel

Answer 5

Depolarising neuromuscular blocking agent that also inhibits cholinesterase, contributing to the neuromuscular effects; causes spastic paralysis, worm detachment and expulsion from the GIT.