Clinical Signs and Symptoms

Class of CompoundsSigns and SymptomsSpecial Notes, Laboratory Evaluations, Specific Treatments, or Antidote
Organophosphate and carbamate insecticides• Nonspecific early symptoms: headache, nausea, vomiting, abdominal pain, and dizziness• Red blood cell and plasma cholinesterase levels
• Sometimes hypersecretion: sweating, salivation, lacrimation, rhinorrhea, diarrhea, and bronchorrhea• Measure nonspecific metabolites for most OPs
• Progressive symptoms: muscle fasciculation, muscle weakness, and respiratory symptoms (bronchospasm, cough, wheezing, and respiratory depression)• Specific metabolites can be measured for chlorpyrifos and parathion
• Bradycardia is typical, although early in acute poisoning, tachycardia may be present• Atropine is primary antidote
• Miosis• Pralidoxime is also an antidote for OP and acts as a cholinesterase reactivator
• Central nervous system: respiratory depression, lethargy, coma, and seizures• Because carbamates generally produce a reversible cholinesterase inhibition, pralidoxime is not indicated in these poisonings
Pyrethroids• Dermal: skin irritation and paresthesia• At times have been mistaken for acute OP or carbamate poisoning and treated with atropine with potentially adverse or disastrous results
• Nonspecific symptoms including headache, fatigue, vomiting, diarrhea, and irritability• Symptomatic treatment
• Similar findings found in OPs, including hypersecretion, muscle fasciculation, pulmonary symptoms and seizures• Vitamin E oil for dermal symptoms
Neonicotinoids• Disorientation, agitation—severe enough to require sedation, drowsiness, dizziness, weakness, and, in some situations, loss of consciousness• Supportive care
• Vomiting, sore throat, abdominal pain• No available antidote
• Ulcerations in upper GI tract• No available diagnostic test
Fipronil (N-phenylpyrazole insecticides)• Nausea and vomiting• Supportive care
• Aphthous ulcers• No available antidote
• Altered mental status and coma• No available diagnostic test
• Seizures
Organochlorines• Central nervous system: mental status changes and seizures• Control acute seizures with lorazepam
• Paresthesia, tremor, ataxia, and hyperreflexia
Glyphosate (phosphonate herbicides)• Nausea and vomiting• Supportive care
• Aspiration pneumonia type syndrome
• Hypotension, altered mental status, and oliguria in severe cases
• Aspiration pneumonia type syndrome
• Pulmonary effects may in fact be secondary to organic solvent
Chlorophenoxy herbicides• Skin and mucous membrane irritation• Consider forced alkaline diuresis with sodium bicarbonate in IV fluids
• Vomiting, diarrhea, headache, confusion
• Metabolic acidosis is the hallmark
• Renal failure, hyperkalemia, and hypocalcemia
Long-acting anticoagulants (rodenticides)• Bleeding: gums, nose, and other mucous membrane sites• Consider PT (INR) or observation
• Bruising• Vitamin K indicated for bleeding (IV vitamin K) or for elevated PT (INR) (oral vitamin K)
  • IV, intravenous.