Understanding Chlorfenapyr Toxicity: An Overview of Acute Human Exposure and Clinical Outcomes

Abstract

Chlorfenapyr is a broad-spectrum pyrrole insecticide. It acts as a pro-insecticide and is metabolized to tralopyril. Acute human chlorfenapyr poisoning is poorly understood, and optimal management after acute exposure is unclear. This review characterizes acute chlorfenapyr poisoning in humans, focusing on its mechanisms, clinical presentation, laboratory findings, imaging results, and treatment strategies. Fifty-six articles were identified. We conducted a literature review using PubMed, Web of Science, Google Scholar, and SpringerLink databases. Chlorfenapyr poisoning can have a latency period of up to 14 days and may cause gradual deterioration over several hours to days, leading to significant morbidity and even death. A serious clinical sign is the development of hyperthermia, likely due to the uncoupling of oxidative phosphorylation by tralopyril. Chlorfenapyr poisoning is characterized by delayed neurological symptoms and a high mortality rate. Laboratory tests often reveal elevated levels of creatine kinase, hepatic aminotransferases, and lactate dehydrogenase. To date, no specific antidotes are available, and treatment remains supportive. When managing cases of acute chlorfenapyr poisoning, physicians must consider the potential latent period of the toxin's effects. This means that even if a patient shows an initial positive response to treatment, healthcare providers should remain vigilant and cannot assume that the patient is completely safe. Continuous monitoring and assessment are essential, as symptoms may still emerge after the initial treatment phase.