12. •Paralysis of the somatic worm musculature
•Inhibit feeding of the parasite by blocking
pharyngeal pumping.
•Disruption of ingestive activity and worm
starvation.
16. Why they are effective for only Parasites???
• Acetylcholine agonists
• The surface of somatic muscle cells of nematodes possess nicotinic
acetylcholine receptors (nAChR) that can be opened by the nicotinic
anthelmintics
• Selective toxicity of these compounds appears to be based on the
unique properties of the nematode nAChR
• They lack subunit lacks the conserved target amino acid residue for
lophotoxin present in all muscle and neuronal AChRs of other
invertebrates and vertebrates.
25. •Pyrazino-isoquinoline ring system of
praziquantel represents a completely novel
structure in anthelmintic therapy with no
relationship to other antiparasitic drug
structures.
•The drug causes an immediate muscle
contraction and vacuolisation of the tegument.