Unit 4.2 Flashcards
Avermectins and milbemycin drugs belong to this general group of antiparasitic drugs.
antinematodals
Ivermectin, selamectin, doramectin, and eprinomectin all belong to this macrolide subgroup of antinematodals.
avermectins
These are the receptors ivermectin and other macrolides stimulate to kill parasites.
glutamate
These receptors are found in the nervous system of mammals and not insects and are also a site where ivermectin and other macrolides can combine and produce toxic effects.
GABA
What special molecule in the blood brain barrier keeps ivermectin and other macrolides out of the brain?
P-glycoprotein
What gene codes for P-glycoprotein? (there are 2 names, know both)
MDR-1 or ABCB1
This term describes how an animal acts if they have a wobbly or drunken gait.
ataxia
This term means pupillary dilation
mydriasis
This was the first macrolide available for use in veterinary medicine
ivermectin
This macrolide is included with pyrantel pamoate for anthelmintic products like Heartgard Plus and Iverhart Plus
ivermectin
This macrolide is a topical endectocide; can be used as a heartworm preventative in both dogs and cats; effective for control of sarcoptic mange in dogs and intestinal hookworms and roundworms in cats
selamectin
A macrolide but not an avermectin used as a once-a-month heartworm preventative in both dogs and cats; also used for treatment of ear mites reflecting its original uses to control agricultural mites
milbemycin oxime
A milbemycin type of macrolide used largely in cattle and horses, but also available as a unique six-month injectable heartworm preventative.
moxidectin
T or F
Stimulation of glutamate receptors cause an increase of activity in the nervous system.
False
T or F
Cats seem particularly sensitive to the ivermectin toxicosis.
False
Blocking a GABA receptor would result in overstimulation of the nervous system.
?
Ivermectin toxicity would be characterized by CNS depression.
True
Glutamate receptors are found in the nervous system of both insects and mammals. However, insecticides that stimulate these glutamate receptors only affect insects and not most mammals. Why?
The glutamate receptors in mammals are in the CNS, behind the blood brain barrier.
Why are collies susceptible to toxicosis from ivermectin, selamectin, and other macrolides?
They have a genetic mutation in the gene that produces P-glycoprotein and this allows the macrolide parasiticides to penetrate the blood brain barrier.
What are the signs of ivermectin toxicosis?
Ataxia, mydriasis, vomiting, salivation
Why aren’t drugs like ivermectin effective against tapeworms or flukes?
Because they don’t have glutamate receptors.
