Postmortem distribution of acephate and its metabolite methamidophos in body fluids and organ tissues of an intoxication case.

We herein report an intoxication case caused by the ingestion of the pesticide Ortoran®, which consists of 50% acephate aqueous solution. A man in his 60 s was found dead in his car with a 100-mL bottle containing approximately 50 mL of Ortoran®. In a gas chromatography - mass spectrometry (GC-MS) screening test, acephate and its metabolite methamidophos were qualitatively detected in his stomach contents. The amounts of acephate and methamidophos (µg/g) in the extract of each body fluid or organ tissue were measured using GC-MS and were as follows: 35.8, 2.84 (heart blood); 44.0, 2.26 (peripheral blood); 2,240, 2.79 (urine); 53.1, 8.91 (brain occipital lobe); 43.7, 2.95 (liver); 102.3, 8.02 (right kidney); and 5450, 22.9 (stomach contents). Based on these results and autopsy findings, the cause of death was concluded to be acute fatal intoxication caused by the pesticide containing acephate and its active metabolite, methamidophos. Concentration ratios between acephate and methamidophos in each body fluid and organ tissue showed higher relative concentrations of brain methamidophos to acephate than those of other organ tissues. A high relative concentration of brain methamidophos may contribute to the intoxication of acephate in humans.

Pesticide-induced quadriplegia in a 55-year-old woman.

Acephate is a commercial organophosphate pesticide formerly used in households and now used primarily for agriculture. Poisoning symptoms include salivation, lacrimation, urination, defecation, gastrointestinal illness, and emesis. In addition to these classic symptoms, neurodegeneration can result from increased and continued exposure of organophosphates. This 55-year-old woman presented with organophosphate-induced delayed neuropathy in the form of quadriplegia due to the commonly used pesticide acephate. She was exposed to this pesticide through multiple sprayings in her work office with underrecognized poisoning symptoms. She presented to her primary care physician with neuropathic pain and paralysis in her arm following the sprayings and eventual complete paralysis. The patient lived for 2 years following her toxic exposure and quadriplegia. A complete autopsy after her death confirmed a transverse myelitis in her spinal cord. We conclude that in susceptible individuals, acephate in excessive amounts can produce severe delayed neurotoxicity as demonstrated in animal studies.