Pyrethrins And Pyrethroids, DEET Flashcards
Pyrethrum comes from??
Daisy like flowers
Used as insecticide
What are the general uses of pyrethrins?
Home and farm insecticides
Farm animals
Flea and tick control
many pyrethrins cannot be used on cats- check formulations*
How are pyrethrins absorbed?
Oral
Dermal
Inhalation
T/F: pyrethrins are highly toxic to mammals
False
Pyrethrins/pyrethrins(synthetic) are one of the safest insecticides due to their relatively low mammalian toxicity
Very toxic to fish (poor metabolism)
What is the difference between pyrethrins and pyrethroids?
Pyrethroids are synthetic analogs on pyrethrins
T/F: a dog treated with pyrethrin that swims in a pond can serve as a source of exposure to fish
True
Canine topical products range from 0.054-65% permethrin
Are cats or dogs more sensitive to pyrethrins?
Cats
-reduced rate of metabolism (deficiency in glucronidase enzyme)
What is the most common exposure route of pyrethrins?
Dermal
Ingestion
How are pyrethrins metabolized and excreted?
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
what is one of the most common causes of poisoning in cats worldwide?
Permethrin
-products for dogs used on cats
What is the MOA of pyrethrin/pyrethroids?
Inhibit closure of Na and K channels —> continual neurotransmitter released —> hyper-excitability of nerve
T/F: pyrethroids formulated wth piperonyl butoxide (non-toxic) appear to have more symptoms than those exposed to pyrethroids alone?
True
Which type of pyrethroids have greater effect on sodium channels?
Type II (a-cyano group)
At high doses, similar to organochlorines, pyrethrins/pyrethroids can have a effect where?
GABA receptor antagonist
T/F: pyrethrins can cause allergic reactions, stimulate adrenal glands, and result in hyperglycemia
True
What are the acute clinical signs due to pyrethrins?
General muscle tremors Depression Blindness Ataxia Lethargy
Salivation Vomiting Diarrhea Hyper excitability Drooling Lip and tongue-numbness
What is the treatment for pyrethrin and pyrethroids??
No specific
Decontamination
Avoid exacerbating toxicity —> control temp/hyperthermia
Symptomatic treatment
- methocarbamol for muscle tremors
- diazepam, barbiturates, propofol CRI
What is the prognosis for pyrethroid toxicity?
Generally good
What is the use of DEET?
Insect repellant
What is the MOA of DEET?
UNKNOWN
Mostly dermal irritation
Disrupt olfactory system of insects
If combined with carbamates —> CNS effects potentiated —> depression
T/F: DEET is designed for human use but can be used in dogs, but not cats.
False
Designed for human use and is NOT recommended for pets, especially cats
What is the dermal absorption of DEET?
7.9-12.8% absorbed
Can increase dermal absorption of other products
Where does DEET accumulated in the body?
Adipose tissue (lipophilic)
What are clinical signs seen in cats and dogs from DEET?
Hyper salivation vomiting hyperexcitability tremors Ataxia seizures
skin and mucous membrane irritation
What is the treatment for DEET ?
No specific antidote Decontamination -dermal - wash -Emesis -activated charcoal
What is the prognosis of DEET exposure
Good if treated in 24-72hrs
T/F: permethrin used in cats is typically applied at 45% without toxicity
False
