II. Mechanism: Insecticide
- Pyrethroids are synthetic Antiparasitic Agents based on Pyrethrins
- Derived from pyrethrum, a chemical found in Chrysanthemum cinerariifolum flowers
- Pyrethroids are highly liphophilic, allowing for the penetration and paralysis of Insects
- Neurotoxic at voltage sensitive Sodium channels, delaying their closure with secondary hyperexcitation
III. Mechanism: Toxicity
- Toxicity is uncommon outside of massive ingestions or Allergic Reaction
- Human absorption may occur with inhalation, ingestion or rarely via skin absorption
-
Half-Life <8 hours
- Extended Half-Life when combined with Piperonyl Butoxide (a synergist added to Pyrethrins, Permethrin)
IV. Medications: Pyrethroid
- Type 1 Pyrethroids (lack cyano group; fast onset, lower Insect kill rate)
- Permethrin
- Allethrin
- Tetramethrin
- Resmethrin
- D-Phenothrin
- Bioresmethrin
- Type 2 Pyrethroids (contain cyano group; slow onset, higher Insect kill rate, less affected by Temperature)
- Cypermethrin
- Cyfluthrin
- Deltamethrin
- Cyphenothrin
- Fenvalerate
- Fluvalinate
V. Adverse Effects: Toxicity with Massive Ingestion or Allergic Symptoms
- Skin and Mucous Membrane
- Irritation
- Urticaria
- Gastrointestinal
- Cardiovascular
- Hypotension
- Tachydysrhythmia
-
Lung
- Cough
- Bronchospasm
- Pulmonary Edema (type 2 Pyrethroids)
- Neurologic
- Headache
- Dizziness
- Hyperreflexia
- Type 1 Pyrethroids
- Type 2 Pyrethroids
- Coarse Tremor
- Choreoathetosis
- Seizures
VI. Management: Toxicity
- See Unknown Ingestion
- Skin Decontamination (soap and water)
-
Hypotension
- Intravenous Fluids
- Norepinephrine for refractory Hypotension
- Seizures
- Disposition
- Medical clearance for discharge at 4 to 6 hours after exposure if no neurologic or cardiopulmonary symptoms
VII. References
- Tomaszewski (2023) Crit Dec Emerg Med 37(6): 32
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Related Studies
Concepts | Injury or Poisoning (T037) |
SnomedCT | 71480005 |
English | Pyrethr insectcd caus tox efft, Pyrethroid intoxication, Pyrethroid toxicity, Pyrethroid insecticide causing toxic effect, Pyrethroid toxicity (disorder) |
Spanish | intoxicación por piretroides (trastorno), intoxicación por piretroides, toxicidad de los piretroides |
Ontology: Pyrethroids (C0597329)
Definition (CSP) | active insecticidal constituents of pyrethrum (Chrysanthemum cinerariifolum) flowers. |
Concepts | Hazardous or Poisonous Substance (T131) , Organic Chemical (T109) , Pharmacologic Substance (T121) |
MSH | D011722 |
SnomedCT | 311846002 |
English | pyrethroid, Pyrethroids, pyrethroids, Pyrethroid insecticide, Pyrethroid insecticide (substance) |
French | Pyréthrinoïdes, Pyréthroïdes |
Spanish | piretroide, insecticida (sustancia), piretroide, insecticida |