A Case of Pyrethroid Poisoning with Clinical Presentation Mimicking Organophosphate Poisoning

Abstract

We report an 89-year-old retired farmer with prolonged bradycardia and hypotension after pyrethroid insecticides ingestion in a suicidal attempt. This patient also had a clinical manifestation mimicking organophosphate poisoning, included confusion, lacrimation and salivation. He required intensive care support, atropine and inotrope infusions treatments. Only metabolites of synthetic pyrethroid insecticides (3-phenoxybenzoic acid and 3-phenoxybenzaldehyde) were detected in the urine sample. In the serum toxicology screening, specific analysis for organophosphate pesticides was negative. He eventually recovered without major sequela. (Hong Kong j.emerg.med. 2016;23:47-51)

Cypermethrin poisoning manifesting with prolonged bradycardia: A case report

“…Activated charcoal administration along with gastric lavage can be performed if the patient presents within an hour of ingestion, however, more evidence is needed to strengthen its use considering the risk of aspiration pneumonia [ 12 , 13 ]. The only case that reported prolonged bradycardia following pyrethroid ingestion was by Cham et al He described a case of toxicity by an unknown amount of pyrethroid with prolonged bradycardia, hypotension and ischemic events and the patient was managed with an infusion of atropine for ten days [ 14 ]. Our case required two bolus doses of the muscarinic antagonist to alleviate bradycardia resulting in complete recovery.…”

Acute Pyrethroids Insecticide Ingestion in An Elderly Patient

“…Life threatening toxicities could be resulted from pyrethroid poisoning. 6,7 The symptoms of acute pyrethroid poisoning in humans are supposed to be subdivided into two classes.…”

“…Measurement of the red cell cholinesterase activity which is reduced in acute organophosphorus poisoning but not in pyrethroid intoxication allows clarification. 6,8 Following ingestion, gastric lavage is probably best avoided since solvents present in many formulations may increase the risk of aspiration pneumonia. Alternatively, although there is only limited experimental evidence that pyrethroid insecticides are adsorbed to charcoal, the administration of active charcoal 50 -100 grams to an adult may be considered if a potentially toxic amount has been ingested within 1 hour.…”

“…Since its presentation mimics organophosphates, thorough history taking, and examinations are needed to manage the intoxication properly. 6…”

Differences in Knowledge, Awareness, Practice, and Health Symptoms in Farmers Who Applied Organophosphates and Pyrethroids on Farms

“…Several studies indicate that OP has a negative impact on human health, nevertheless, the data pertinent to PY toxicity is inconsistent (20,21). Organophosphate inhibits acetylcholinesterase leading to excessive activity at acetylcholine receptors.…”