Pyrethrins And Pyrethroids, DEET Flashcards Preview

RUSVM Toxicology > Pyrethrins And Pyrethroids, DEET > Flashcards

Flashcards in Pyrethrins And Pyrethroids, DEET Deck (27)
Loading flashcards...
1
Q

Pyrethrum comes from??

A

Daisy like flowers

Used as insecticide

2
Q

What are the general uses of pyrethrins?

A

Home and farm insecticides
Farm animals

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

3
Q

How are pyrethrins absorbed?

A

Oral
Dermal
Inhalation

4
Q

T/F: pyrethrins are highly toxic to mammals

A

False

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

Very toxic to fish (poor metabolism)

5
Q

What is the difference between pyrethrins and pyrethroids?

A

Pyrethroids are synthetic analogs on pyrethrins

6
Q

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

A

True

Canine topical products range from 0.054-65% permethrin

7
Q

Are cats or dogs more sensitive to pyrethrins?

A

Cats

-reduced rate of metabolism (deficiency in glucronidase enzyme)

8
Q

What is the most common exposure route of pyrethrins?

A

Dermal

Ingestion

9
Q

How are pyrethrins metabolized and excreted?

A

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

10
Q

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

A

Permethrin

-products for dogs used on cats

11
Q

What is the MOA of pyrethrin/pyrethroids?

A

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

12
Q

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

A

True

13
Q

Which type of pyrethroids have greater effect on sodium channels?

A

Type II (a-cyano group)

14
Q

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

A

GABA receptor antagonist

15
Q

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

A

True

16
Q

What are the acute clinical signs due to pyrethrins?

A
General muscle tremors
Depression 
Blindness
Ataxia 
Lethargy 
Salivation
Vomiting
Diarrhea
Hyper excitability 
Drooling
Lip and tongue-numbness
17
Q

What is the treatment for pyrethrin and pyrethroids??

A

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

Symptomatic treatment

  • methocarbamol for muscle tremors
  • diazepam, barbiturates, propofol CRI
18
Q

What is the prognosis for pyrethroid toxicity?

A

Generally good

19
Q

What is the use of DEET?

A

Insect repellant

20
Q

What is the MOA of DEET?

A

UNKNOWN
Mostly dermal irritation

Disrupt olfactory system of insects

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

21
Q

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

A

False

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

22
Q

What is the dermal absorption of DEET?

A

7.9-12.8% absorbed

Can increase dermal absorption of other products

23
Q

Where does DEET accumulated in the body?

A

Adipose tissue (lipophilic)

24
Q

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

A
Hyper salivation
vomiting
hyperexcitability
tremors
Ataxia 
seizures

skin and mucous membrane irritation

25
Q

What is the treatment for DEET ?

A
No specific antidote 
Decontamination 
-dermal - wash
-Emesis 
-activated charcoal
26
Q

What is the prognosis of DEET exposure

A

Good if treated in 24-72hrs

27
Q

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

A

False