Neonicotinoid insecticides: an emerging cause of acute pesticide poisoning

Abstract

Introduction. Neonicotinoids are a relatively new class of insecticides. They exhibit agonistic effects at postsynaptic nicotinic receptors in insects and are believed to have low toxicity in humans. Methods. We conducted a retrospective analysis of all neonicotinoid exposures reported to the Taiwan National Poison Center to better understand the toxicity profile of neonicotinoid insecticides. Results. A total of 70 patients were analyzed. Most exposures involved suicidal ingestions of imidacloprid alone. Clinical manifestations of neonicotinoid insecticide toxicity bear some resemblance to those of acute nicotine poisoning. Although most exposures were of mild-to-moderate severity, eight patients developed major effects and two died. Aspiration pneumonia and respiratory failure were the main cause of severe toxicity. Conclusion. Significant toxicity of neonicotinoids can occur following large amount of oral ingestion. Poisoned patients may present with cholinergic syndrome, and judicious use of atropine seems justified. Symptomatic treatment, especially ventilator support, remains most important in clinical management.

Keywords :

• Acute poisoning
• Cholinergic syndrome
• Imidacloprid
• Neonicotinoid insecticide
• Nicotinic receptor