Anthelmintics Flashcards
What are the 5 main groups of broad spectrum anthelmintics?
Benzimadoles, Imidathiozoles, Macrocyclic Lactones/Tetrahydropyramidines, Spiroindoles, Amino acetonitrile derivatives.
How do Benzimadoles work? What are they also known as?
Benzimadoles are also known as ‘white drenches’. They bind to parasite tubulin and inhibit glucose upake, cause glycogen depletion and death.
Give an example of some drugs that are Benzimadoles. What parasites are they active against? What type of products are they?
E.g.: Fenbendazole, Triclabendazole. They are active against round worms and tapeworms, NOT flukes. They are oral products only. Potency determined by duration of exposure.
How do Imidathiozoles work? What are they also known as?
AKA ‘Yellow drenches’. They are cholinergic antagonists, so cause rapid and reversible spastic paralysis.
Give an example of some drugs that are Imidathizoles. What parasites are they active against? What is their activity like?
E.g. Levimasole, Active against nematodes (roundworms). VERY short half life, no residual activity.
How do Macrocyclic Lactones work? What are they also known as?
AKA ‘Clear drenches’. Open invertebrate glutamate chloride channels causing flaccid paralysis.
Give an example of some drugs that are Macrocyclic Lactones. What parasites are they active against? What is their activity like?
E.g. Avermectins (ivermectin, selamectin), Milbemycins (moxidectin etc.). Active against Nematodes and arthropods. Have a persistent effect so can be used metaphylactically or prophylactically.
What are tetrahydropyramidines? Give an example, what are they active against?
AKA ‘Yellow drenches’. Example = pyrantel. Active against roundworms (nematodes), and tape worms.
What are Salicylanides? Give an example of them. How do they work?
E.g. Closantel. They are used against flukes (not in milking cows and sheep), have a long activity and decrease availability of phosphate.
How does Praziquantel work? What is it used against?
Praziquantel destroy the tegument esp. where attaches. Used against tapeworms, especially Hydatid disease.
What groups of drugs (broad and narrow) would you consider for roundworms (nematodes)?
Benzimadoles, Imidazothiozoles, Macrocyclic lactones, Pyrantel (broad) and depsipeptides, salicyclanides, piperazines etc. (narrow)
What groups of drugs (broad and narrow) would you consider for tapeworms (cestodes)?
Benzimadoles, Pyrantel (THP) (broad) and Isoquinolones (Praziquantel etc.) etc. (narrow)
What groups of drugs (broad and narrow) would you consider for flukes?
No broad spectrum. Salicylanides and substituted phenols (nitroxynil) - narrow.
