A case report of fatal chlormequat poisoning: Identification of potential additional mechanism of toxicity.

Chlormequat is a quaternary ammonium salt used as a plant growth-regulating agent. It is structurally similar to choline, acting at muscarinic and nicotinic receptors. Herein, we present the case of suicidal poisoning with an unknown dose of chlormequat by a 45-year-old woman. Initially, carbofuran was suspected of ingestion. Following ingestion, circulatory arrest occurred. After hospital admission, gastric lavage was performed, and activated charcoal was administered. Initial toxicological analysis identified mild alcohol intoxication, while high-resolution mass spectrometry later discovered a high concentration of chlormequat in the blood and urine. Continuous hemodialysis was indicated to accelerate chlormequat elimination. Antioxidant and Cytosorb therapy were applied to reduce oxidative stress and inflammation. Laboratory results further showed that chlormequat is a mild acetylcholinesterase inhibitor, revealing an additional mechanism of toxicity. However, despite all initial efforts, deep coma persisted with clinical signs of areflexia above C1 and malignant brain edema described on the CT scan. The patient died on day 3 of the ICU stay in palliative care. The authors present complete laboratory and toxicological results, including toxicokinetic data, oxidative stress parameters, acetylcholinesterase, and butyrylcholinesterase activity. In conclusion, modern analytical methods are necessary to provide more effective targeted treatment and could help uncover previously unknown mechanisms of toxicity.