Organophosphates Acephate (Orthene) Chlorphoxim (Baythion-C) Chlorpyrifos (Dursban, Lorsban) Diazinon Dimethoate (Cygon, DeFend) Ethoprop (Mocap) Fenitrothion (Sumithion) Fenthion (Baytex) Malathion (Cythion) Naled (Dibrome) Terbufos (Counter)
| Inhibit cholinesterase leading to excess acetylcholine | CNS—anxiety, seizures, Skeletal nerve-muscle junctions, autonomic ganglia—twitching, tachycardia, muscle weakness (nicotinic effects); peripheral cholinergic neuroeffector unctions— “all faucets on”— sweating, salivation, diarrhea, tearing (muscarinic effects); miosis (pinpoint pupils) most commonly, but 15 percent have mydriasis secondary to epinephrine release from adrenals due to nicotinic receptor stimulation. | Draw red cell cholinesterase and plasma pseudocholinesterase levels before therapy. Do not delay treatment while awaiting results. Maintain and protect airway. Supplemental oxygen Atropine (preservative-free, if possible), 2 to 5 mg IV every 15 minutes (adults and children >12 years) until pulmonary symptoms controlled; children < 12 years, 0.05 to 0.1 mg/kg every 15 minutes; doses repeated as needed for symptom control (up to 24 hours, taper dose) Pralidoxime (2-PAM, Protopam) IV, 1 to 2 g (adults) over 10 minutes, 20 to 50 mg/kg (<12 years) over 30 minutes; repeated in 1 to 2 hours and at 10- to 12-hour intervals as needed for symptom control; alternatively: continuous IV infusion 10 to 20 mg/kg/hr (up to 500 mg/hr) after initial bolus and continued for 24 hours Furosemide (Lasix), 40 to 160 mg IV for pulmonary congestion remaining after full atropinization Benzodiazepine for seizures (diazepam [Valium]), 5 to 10 mg slow IV push, repeated every 5 to 10 minutes to control or maximum 30 mg in adults; 0.2 to 0.5 mg/kg IV every 5 minutes to maximum of 10 mg in children >5 years, 5 mg in children <5 years; lorazepam may also be used
|
| | | | |
Carbamates | Reversible Cholinesterase Inhibition (carbamoyl-acetylcholinesterase [AChE] complex Dissociates much more easily and quickly than OP-AChE complex) | Cholinergic crisis with “all faucets on”; CNS depression with coma, seizures, hypotonicity in serious toxic exposures | Maintain and protect airway. Optimize oxygenation/supplemental oxygen. Atropine IV (preferably or IM) Adults, children >12 years, 2.0 to 4.0 mg every 15 minutes until secretions controlled; children <12 years, 0.05 to 0.10 mg/kg every 15 minutes until secretions controlled; continue 2 to 12 hours; continued signs of poisoning indicate need for more atropine. Furosemide (Lasix), 40 to 160 mg, if basilar rales persist after atropinization Pralidoxime not indicated in pure carbamate poisoning; may be necessary in mixed organophosphate/carbamate poisoning or unknown poisoning with cholinergic syndrome.
|
| | | | |
Organochlorines Chlorobenzilate Dicofol (Kelthane) Dienochlor (Pentac) Endosulfan Lindane (Kwell)
| Induction of hyperexcitable state in central and peripheral nervous system by disruption of normal flow of sodium and potassium across the axon membrane; may antagonize GABA-mediated inhibition in CNS | Seizures, headache, dizziness, nausea, vomiting, paresthesias, incoordination, tremor/twitching following topical treatment for lice/scabies or accidental or intentional ingestion of liquid pesticide | Maintain and protect airway. Ensure adequate oxygenation. Seizure control with diazepam; adults, 5 to 10 mg IV push over 2 to 5 minutes, repeated every 10 minutes as necessary; children, <12 years 0.04 to 0.2 mg/kg every 10 minutes, monitoring airway closely; lorazepam may be used as an alternative. IV fluids with dextrose (5 to 10 percent) and thiamine 100 to 500 ng/L Dysrhythmias from rare myocardial irritant effect treated with lidocaine (1 mg/kg bolus, 2 to 4 mg/minute continuous infusion)
|
| | | | |
Biocides Pyrethrins/pyrethroids Allethrin Cyfluthrin (Baythroid) Cypermethrin (Barricade, Cymbush, Cynoff, Demon) Deltamethrin Dimethrin Fenothrin Fenvalerate Permethrin (Ambush, Dragnet, Nix, Pounce) Remethrin
| Pyrethrins are derived from chrysanthemums; pyrethroids are synthetic compounds with longer half-lives; both can produce toxic effects on the nervous system but are not well absorbed and are effectively and quickly detoxified by mammalian liver enzyme systems. | The most severe symptoms are seizures, though highly uncommon unless highly exposed (usually through ingestion of large quantities); tremor, incoordination, salivation, vomiting; topical exposure can produce short-term paresthesias, especially of the hands and face; a small portion of the population (1 to 3 percent) is allergic to pyrethrins/pyrethroids—resulting in symptoms ranging from nasal stuffiness to asthma. | Skin decontamination by thorough washing with soap and water is suggested; vitamin E oil preparations are effective in preventing and treating paresthesias; corn oil and petrolatum are less effective. Seizures controlled with benzodiazepines. Standard antiallergy therapy for hypersensitivity reactions.
|
| | | |
| | | | |
Bacillus thuringiensisVariety aizawai (Agree, Mattch) Variety israelensis (Aquabac, Skeetal) Variety kurstaki (Bactur, Dipel)
| Wide range of products derived from several varieties of this organism; highly limited effects on mammalian systems | Mild irritative pulmonary symptoms in some involved in manufacturing process, not in mixers or appliers; theoretical risk of respiratory infection in immunocompromised individuals; single corneal ulceration reported, successfully treated with standard antibiotics; mild gastroenteritis with heavy ingestion | Symptomatic treatment following decontamination
|
| | | | |
Repellants Diethyltoluamide—DEET (Muskol, Off!, Skeeter Beater, Skeeter Cheater, Skintastic for Kids, others) | Mechanism of toxicity unknown | CNS depression followed by seizures; rare unless applied excessively under occlusion; mild skin irritating effects with repeated use; corneal and mucosal irritation; nausea and vomiting with ingestion and, rarely, hypotension, tachycardia with heavy dermal exposure | Decontamination Control of seizures with benzodiazepines Supportive care
|
| | | | |