Pesticides

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Pesticides
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insecticides

• Organophosphates irreversibly bind to
  acetylcholinestrase (aging)
• Aging occurs over minutes to hours, and when it
  does the enzymatic activity of the cholinesterase
  is destroyed and symptoms will persist weeks
  until new enzyme is made.
• Antidote must be given before aging.

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Clinical features
S Salivation
L Lacrimation
U Urinary incontinence
D Defecation
G GI pain
E Emesis

D Defecation
U Urination
M Muscle weakness, miosis
B Bradycardia, bronchorrhea, bronchospasm
E Emesis
L Lacrimation
S Salivation

Killer Bees Bradycardia, bronchorrhea, bronchospasm
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diagnosis

• Clinical
• Can check plasma cholinesterase levels

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Decontamination Protective clothing must be worn to prevent secondary poisoning of health care workers.
Decontamination Handle and dispose of all clothes as hazardous waste.
Decontamination Wash patient with soap and water.
Decontamination Handle and dispose of water runoff as hazardous waste.
Monitoring Cardiac monitor, pulse oximeter, 100 oxygen.
Gastric lavage No proven benefit (see text).
Activated charcoal No proven benefit (see text).
Urinary alkalinization No proven benefit (see text).
Atropine 1 milligram or more IV in an adult or 0.010.04 milligram/kg (but never lt0.1 milligram) IV in children. Repeat every 5 min until tracheobronchial secretions attenuate.
Pralidoxime 12 grams for adults or 2040 milligrams/kg (up to 1 gram) in children, mixed with normal saline and infused IV over 5 to 10 min.
Pralidoxime Continuous infusion often necessary.
Seizures Benzodiazepines.


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treatment

• Atropine antagonizes acetylcholine and blunts the
  muscarinic effects
• No effect on the muscle weakness
• Pralidoxime displaces the organophashate from the
  active site on the acetylcholinesterase,
  ameliorating the muscarinic, nicotinic, and
  central neurologic symptoms

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carbamates

• physostigmine, pyridostigmine, and neostigmine.
• Reversibly inhibits cholinesterase enzyme
• Symptoms last much less time (4-8 hours)
• Treat symptoms with atropine, but hold
  pralidoxime if known carbamate

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herbicides


Herbicides
Chlorophenoxy compounds
Bipyridyls
Paraquat
Diquat
Urea-substituted
Organophosphates
Glyphosate
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paraquat

• The lethal oral dose of the 20 solution is 10 to
  20 mL in an adult and 4 to 5 mL in a child.
• local skin irritation and ulceration of
  epithelial surfaces
• Supportive treatment to prevent pulmonary
  toxicity
• Immediate gi decontamination indicated
• High mortality

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rodenticides

• Most one-time warfarin rodenticide ingestions are
  insignificant accidental poisonings and do not
  cause any bleeding problems.
• Significant coagulopathy requires large amounts
  in a single exposure or a repetitive exposure
  over several days

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treatment

• Activated charcoal if potentially severe
  intoxication
• Vitamin K if INR is greater than 2 times normal

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References

• Tintinalli, Ch. 195