Anthelmintics Flashcards
Define Anthelmintic
A chemotherapeutic agent used to control helminth infections
Define Chemotherapy
Use drugs to injure an invading organism without injury to the host - selective toxicity dependent
Anthelmintic action can have a ____ or a ____ spectrum
broad or narrow
What is the proper name for white drench? Give a specific example
Benzimidazoles - fenbendazole
What is the proper name for yellow drench? Give a specific example
Imidazothiazoles - levamisole
What is the proper name for clear drench? Give a specific example
Macrocyclic lactones - ivermectin
How do Benzimidazoles act on a helminth?
Block microtubule polymerisation causing inhibition of glucose intake = death
Give an example of a benzimidazoles Anthelmintic used against liver fluke
Triclabendazole
What is potency of Benzimidazoles determined by?
Duration of drug exposure
Will benzimidazoles be more potent in a dog or a ruminant? Why?
Ruminant - slower rate of passage of ingesta so longer exposure
How do Imidazothiazoles act on a helminth? How?
They cause spastic paralysis - accelerate neurotransmission
Give an example of an Imidazothiazole
Levamisole
How do Macrocyclic Lactones act on helminths? How?
They cause flaccid paralysis - blocking neurotransmission
What two types of Macrocyclic Lactones are there?
Avermectins and Milbemycins
Define Metaphylaxis treatment
Treatment of an animal whilst they are being exposed to the helminth