Pyrethrins intoxication Flashcards
(6 cards)
Why cats seem so sensitive to pyrethrins
Cats have a relatively high surface area to weight ratio which means that they receive higher doses on a mg/kg basis
The reduced capacity of cats for glucuronidation can contribute to the accumulation of metabolites and a less efficient detoxification process
What is the mechanism of toxicity of pyrethroids
The lipophilic pyrethroids are quickly absorbed through the skin into the systemic circulation
- their absorption is also rapid after oral intake and even inhalation
Pyrethroids principally affect the peripheral and central nervous system by leading to repetitive firing of the nerve fiber
- due to their lipophilic properties, pyrethrins pass easily through the blood-brain barrier and can induce CNS signs , including seizures
What are the clinical signs of pyrethrin intoxication
Clinical signs are normally noticed immediately after exposure but can be delayed for up to 72 h
The most common clinical signs are:
- tremors/muscle fasciculations
- twitches
- hyperesthesia
- seizures
- ptyalism
- ataxia
What is one of the principal differential diagnoses for pyrethrin intoxication
Organophosphate/carbamate toxicosis
- low doses of atropine should not alleviate any signs in the carbamate-intoxicated patient
What would be your treatment plan for pyrethrin intoxication
Dermal decontamination should be instituted as soon as possible
- the patient should be actively dried and temperature monitored because hypothermia may potentiate the effect of pyrethroids on ion-channel activity
There is a positive effectv of activated charcoal even after dermal exposure
- this may be due to the existence of some enterohepatic recirculation
Benzodiazepines are typically insufficient to control signs in severe intoxications and may also be responsible for paradoxical exacerbation of neurological signs
Methocarbamol is a peripherally acting muscle relaxant that is recommended for control of severe muscle tremors
- 55-220 mg/kg, IV
- doses should not exceed 330 mg/kg/day
Why activated charcoal is not useful for pyrethrin intoxication
Because pyrethrins are quickly metabolized and are not stored in the body
