Unit 4.2

Question 1

Avermectins and milbemycin drugs belong to this general group of antiparasitic drugs.

Answer 1

antinematodals

Question 2

Ivermectin, selamectin, doramectin, and eprinomectin all belong to this macrolide subgroup of antinematodals.

Answer 2

avermectins

Question 3

These are the receptors ivermectin and other macrolides stimulate to kill parasites.

Answer 3

glutamate

Question 4

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.

Answer 4

GABA

Question 5

What special molecule in the blood brain barrier keeps ivermectin and other macrolides out of the brain?

Answer 5

P-glycoprotein

Question 6

What gene codes for P-glycoprotein? (there are 2 names, know both)

Answer 6

MDR-1 or ABCB1

Question 7

This term describes how an animal acts if they have a wobbly or drunken gait.

Answer 7

ataxia

Question 8

This term means pupillary dilation

Answer 8

mydriasis

Question 9

This was the first macrolide available for use in veterinary medicine

Answer 9

ivermectin

Question 10

This macrolide is included with pyrantel pamoate for anthelmintic products like Heartgard Plus and Iverhart Plus

Answer 10

ivermectin

Question 11

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

Answer 11

selamectin

Question 12

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

Answer 12

milbemycin oxime

Question 13

A milbemycin type of macrolide used largely in cattle and horses, but also available as a unique six-month injectable heartworm preventative.

Answer 13

moxidectin

Question 14

T or F

Stimulation of glutamate receptors cause an increase of activity in the nervous system.

Answer 14

False

Question 15

T or F

Cats seem particularly sensitive to the ivermectin toxicosis.

Answer 15

False

Question 16

Blocking a GABA receptor would result in overstimulation of the nervous system.

Answer 16

?

Question 17

Ivermectin toxicity would be characterized by CNS depression.

Answer 17

True

Question 18

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?

Answer 18

The glutamate receptors in mammals are in the CNS, behind the blood brain barrier.

Question 19

Why are collies susceptible to toxicosis from ivermectin, selamectin, and other macrolides?

Answer 19

They have a genetic mutation in the gene that produces P-glycoprotein and this allows the macrolide parasiticides to penetrate the blood brain barrier.

Question 20

What are the signs of ivermectin toxicosis?

Answer 20

Ataxia, mydriasis, vomiting, salivation

Question 21

Why aren’t drugs like ivermectin effective against tapeworms or flukes?

Answer 21

Because they don’t have glutamate receptors.