Pyrethrins And Pyrethroids, DEET

Question 1

Pyrethrum comes from??

Answer 1

Daisy like flowers

Used as insecticide

Question 2

What are the general uses of pyrethrins?

Answer 2

Home and farm insecticides
Farm animals

Flea and tick control
many pyrethrins cannot be used on cats- check formulations*

Question 3

How are pyrethrins absorbed?

Answer 3

Oral
Dermal
Inhalation

Question 4

T/F: pyrethrins are highly toxic to mammals

Answer 4

False

Pyrethrins/pyrethrins(synthetic) are one of the safest insecticides due to their relatively low mammalian toxicity

Very toxic to fish (poor metabolism)

Question 5

What is the difference between pyrethrins and pyrethroids?

Answer 5

Pyrethroids are synthetic analogs on pyrethrins

Question 6

T/F: a dog treated with pyrethrin that swims in a pond can serve as a source of exposure to fish

Answer 6

True

Canine topical products range from 0.054-65% permethrin

Question 7

Are cats or dogs more sensitive to pyrethrins?

Answer 7

Cats

-reduced rate of metabolism (deficiency in glucronidase enzyme)

Question 8

What is the most common exposure route of pyrethrins?

Answer 8

Dermal

Ingestion

Question 9

How are pyrethrins metabolized and excreted?

Answer 9

Hydrolysis and oxidation in blood and liver
(Presence of A-cyano moiety on type II pyrethroids decreases rate of hydrolysis)

Conjugated metabolites are usually excreted in urine within 24hrs

Question 10

what is one of the most common causes of poisoning in cats worldwide?

Answer 10

Permethrin

-products for dogs used on cats

Question 11

What is the MOA of pyrethrin/pyrethroids?

Answer 11

Inhibit closure of Na and K channels —> continual neurotransmitter released —> hyper-excitability of nerve

Question 12

T/F: pyrethroids formulated wth piperonyl butoxide (non-toxic) appear to have more symptoms than those exposed to pyrethroids alone?

Answer 12

True

Question 13

Which type of pyrethroids have greater effect on sodium channels?

Answer 13

Type II (a-cyano group)

Question 14

At high doses, similar to organochlorines, pyrethrins/pyrethroids can have a effect where?

Answer 14

GABA receptor antagonist

Question 15

T/F: pyrethrins can cause allergic reactions, stimulate adrenal glands, and result in hyperglycemia

Answer 15

True

Question 16

What are the acute clinical signs due to pyrethrins?

Answer 16

General muscle tremors
Depression 
Blindness
Ataxia 
Lethargy 

Salivation
Vomiting
Diarrhea
Hyper excitability 
Drooling
Lip and tongue-numbness

Question 17

What is the treatment for pyrethrin and pyrethroids??

Answer 17

No specific
Decontamination
Avoid exacerbating toxicity —> control temp/hyperthermia

Symptomatic treatment

• methocarbamol for muscle tremors
• diazepam, barbiturates, propofol CRI

Question 18

What is the prognosis for pyrethroid toxicity?

Answer 18

Generally good

Question 19

What is the use of DEET?

Answer 19

Insect repellant

Question 20

What is the MOA of DEET?

Answer 20

UNKNOWN
Mostly dermal irritation

Disrupt olfactory system of insects

If combined with carbamates —> CNS effects potentiated —> depression

Question 21

T/F: DEET is designed for human use but can be used in dogs, but not cats.

Answer 21

False

Designed for human use and is NOT recommended for pets, especially cats

Question 22

What is the dermal absorption of DEET?

Answer 22

7.9-12.8% absorbed

Can increase dermal absorption of other products

Question 23

Where does DEET accumulated in the body?

Answer 23

Adipose tissue (lipophilic)

Question 24

What are clinical signs seen in cats and dogs from DEET?

Answer 24

Hyper salivation
vomiting
hyperexcitability
tremors
Ataxia 
seizures

skin and mucous membrane irritation

Question 25

What is the treatment for DEET ?

Answer 25

No specific antidote 
Decontamination 
-dermal - wash
-Emesis 
-activated charcoal

Question 26

What is the prognosis of DEET exposure

Answer 26

Good if treated in 24-72hrs

Question 27

T/F: permethrin used in cats is typically applied at 45% without toxicity

Answer 27

False