Pesticides
Organophosphates
Block ACh-esterase
SLUDGE
Diarrhea, diaphoresis
Urination
Miosis
Bradycardia, bronchosecretions, bronchostriction
Emesis
Lacrimation
Salivation
Nicotinic effects can give mydriasis, fasiculations, and paralysis
Confusion and coma
Can be brady or tachycardic
Strong Rancid Odor, Garlic-like
Some labs can run cholinesterase levels, get plasma and RBC (for chronic intox)
Decon-can penetrate latex, use rubber gloves
Supportive Rx
Atropine (for muscarinic effects) 5mg IV Q5 minutes until control of mucosal secretions
May need up to 500 mg in the first hour, followed by 100 mg per hour\
better method is to start with 3 mg and double every 5 minutes until desired response (J Med Toxicol 2012;8:108-117.)
Pralodoxime (2-Pam)
1-2 grams (2550 mg/kg) IV over 15 minutes, then 500 mg/hr. Must be given early as once acetylcholinesterase ages, 2-Pam will not work. Can cause arrest if given rapidly.
Cont infusion is better Lancet. 2006 Dec 16;368(9553):2136-41. FINDINGS: 100 patients were assigned the high-dose regimen, and 100 the control regimen. There were no drop-outs. Patients receiving the high-dose pralidoxime regimen required less atropine during the first 24 h than controls (median 6 mg vs 30 mg; difference 24 mg [95% CI 24-26, p<0.0001]). 88 (88%) and 64 (64%) of controls and high-dose patients, respectively, needed intubation during admission to hospital (relative risk=0.72, 0.62-0.86, p=0.0001). Control patients required ventilatory support for longer (median 10 days vs 5 days; difference 5 days [5-6, p<0.0001]). INTERPRETATION: A high-dose regimen of pralidoxime, consisting of a constant infusion of 1 g/h for 48 h after a 2 g loading dose, reduces morbidity and mortality in moderately severe cases of acute organophosphorus-pesticide poisoning.
Intermediate Syndrome: It occurs after initial symptoms of cholinergic excess have resolved, but before the development of delayed peripheral neurological deficits that may take days or weeks to occur, thus the name “Intermediate Syndrome”
Carbamate Insecticides
Same as organophosphates, but only last a few hours. May not need 2-Pam as they bind AChase reversibly, but probably still safer to give as only animal studies exist.
Chlorinated Hydrocarbons
DDT, Lindane, etc.
sensitize heart to catecholamines, seizures
Pyrethrins and Pyrethroids
Permethrin, cypermethrin, deltamethrin, fenvalerate
Can cause paresthesias, allergic rxns, coma, fasiculations, seizures, NCPE
Decon and supportive care
Nicotine
Green tobacco sickness gi sx, HA, dizziness, and diaphoresis.
Deet
Seizures, coma, neurotoxicity. But remarkably safe considering widespread use.
Substituted Phenols
uncouple oxidative, can cause hyperthermia
Pyrimidifen Intoxication (Annals EM 42:2, 2003)
some similarities to organophosphates. Causes circulatory shock. At this point, only symptomatic treatment can be offered.
Back to topHerbicides
Paraquat
used to spray marijuana fields, activated by sunlight, inactive by burning, harvest at night and your crop is still good.
Highly tissue toxic
Direct pulmonary destruction
GI ulcers and possible esophageal rupture
Acute renal failure from proximal tubule destruction
Free radical formation
Aggressive orogastric Lavage in first 1-2 hours even if asymptomatic
AC
Avoid O2 if possible to decrease free radicals
Fullers Earth to inactivate unabsorbed paraquat
Use charcoal hemoperfusion
Consider pulse steroids and cyclophosphamide
Diquat
Similar ot above in presentation and management, but need higher doses to be toxic
Chlorphenoxy Acids
agent orange
Nausea, diarrhea, abd pn, ataxia, paralysis, coma, rhabdo
Back to topRodenticides
Aldicarb
Tres pasitos (three steps), illegally imported from the DR
Red squill
Arsenic
Thallium, tetramine
Strychnine, sodium monofluoroacetate (compound 1080)
Barium, bromethalin
Phosphides, phosphorous (yellow or white), PCNU
Arsenic
Norbormide
Indanediones
Coumadin-like anticoagulants
Red Squill
cardiac glycoside from sea onion. Very powerful emetic so most ingestions self-decontaminate
Alpha-napthyl thiourea (ANTU)
Increases capillary permeability in the lungs
Dyspnea, rales, NCPE
No antidote
TETS
tetramethylenedisulfotetramine
called dushuqiang in china
severe seizures
odorless, tasteless water soluble powder
gaba antagonist, irreversibly binds
lethal dose 7-10 mg
also consider thallium which can present with gi symptoms, alopecia and neuropathies
Strychnine
Nausea, usually without vomiting
Muscle hyperexcitability, hyperreflexia, convulsions without loss of consciousness
Benzos, supportive care
PNU (Vacor )
Kills pancreatic beta cells
Causes DKA
Treat with niacinamide, no longer available IV, po at supplement stores
Arsenic trioxide
heavy metal which causes gi symptoms and cardiovascular collapse
Norbomide
stimulates rat-specific smooth muscle receptor causing intense vasoconstriction
not toxic to humans
Indanediones
substances such as chlorphacinone and pindone are non-coumadin anticoagulants
Coumarins
Superwafarins
Inhibits vit k dependant activation of factors II,VII,IX,X by preventing regeneration of Vit K.
Bleeding
AC
Vitamin K1 (not K3)
Consider FFP
In kids, get a baseline PT, if normal bring them back in 48 hrs for repeat. If normal, you are done. If abnormal then give Vit K.
Good prospective study of doing nothing (Ann Emerg Med 40(1) 2002)
To read Leon Gussow’s 2005 Emergency Medicine News column on “Weapons of Mouse Destruction”, click here.
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