Acute chlorfenapyr toxicity in 3 dogs from a single household

Suspected chlorfenapyr poisoning in a horse

Chlorfenapyr is a pesticide that interferes with mitochondrial function, leading to cell death and mortality. Although poisoning is primarily documented in humans and dogs, it can result in severe clinical signs, including sweating, respiratory distress, and neurological dysfunction. This report describes the clinical and laboratory findings of a horse with suspected accidental intoxication with chlorfenapyr. A 4-year-old Quarter Horse mare was referred to the veterinary hospital with signs of excessive sweating, hyperthermia, tachypnea, muscle fasciculation, and fearful facial expression. The clinical signs appeared a day after the paddock where the horse grazed was sprayed with chlorfenapyr for caterpillar control. Despite initial abnormalities in renal and liver profiles in the serum biochemistry analysis, the horse responded positively to supportive treatment with intravenous fluid therapy, sodium dipyrone (25mg/kg QID), and cold-water showers, showing improvement in clinical parameters, and was discharged without further complications.

Chlorfenapyr-related delayed rhabdomyolysis: a case series

Introduction

Chlorfenapyr, a broad-spectrum insecticide and acaricide of the pyrrole-class pesticides, can induce dizziness, fatigue, profuse sweating, and altered consciousness by interfering with cell energy metabolism. However, chlorfenapyr-related rhabdomyolysis has rarely been reported.

Case presentations

Patient 1 was a healthy 26-year-old man who ingested approximately 30 mL of chlorfenapyr. After gastric lavage, rehydration, diuresis, liver protection, and symptomatic treatment, he was discharged. However, he was readmitted 11 days later with rhabdomyolysis and acute kidney injury, and his blood tralopyril level was 187 μg/mL. Patient 2 was a 43-year-old man who consumed approximately 50 mL of chlorfenapyr without seeking medical care for 6 days. On day 7, his blood chlorfenapyr and tralopyril levels were 42 μg/mL and 542 μg/mL, respectively. Subsequently, the patient was diagnosed with rhabdomyolysis and brainstem injury.

Discussion

Chlorfenapyr can disrupt cellular energy metabolism, leading to rhabdomyolysis and brainstem injury, and physical activity may trigger and accelerate rhabdomyolysis. The delayed damage caused by chlorfenapyr poisoning may be attributed to the gradual depletion of cellular energy and prolonged presence of its metabolites in the body.

A clinical warning in the treatment of chlorfenapyr poisoning

Chlorfenapyr, an arylpyrrole-based insecticide, disrupts mitochondrial oxidative phosphorylation to deprive the target organism of energy. Chlorfenapyr poisoning in humans causes distinct clinical signs such as hyperhidrosis, malignant hyperthermia, rhabdomyolysis, and delayed neurological symptoms that worsen over time and can be fatal. When treating acute chlorfenapyr poisoning, physicians must consider the latent period and not assume that a patient is safe after an initial response to treatment. It is important to take measures before sudden, fatal symptoms appear. This paper presents three cases of chlorfenapyr poisoning as a warning for physicians to understand its clinical course and treatment.

A Comprehensive Review of the Current Knowledge of Chlorfenapyr: Synthesis, Mode of Action, Resistance, and Environmental Toxicology

Creating new insecticide lead compounds based on the design and modification of natural products is a novel process, of which chlorfenapyr is a typical successful example. Chlorfenapyr is an arylpyrrole derivative that has high biological activity, a wide insecticidal spectrum, and a unique mode of action. For decades, a series of chlorfenapyr derivatives were designed and synthesized continuously, of which many highly active insecticidal compounds were discovered sequentially. However, due to the widespread application of chlorfenapyr and its degradation properties, some adverse effects, including pest resistance and environmental toxicity, occurred. In this review, a brief history of the discovery and development of chlorfenapyr is first introduced. Then, the synthesis, structural modification, structure activity relationship, and action mechanism of arylpyrroles are summarized. However, challenges and limitations still exist, especially in regard to the connection with pest resistance and environmental toxicology, which is discussed at the end of this review. This comprehensive summary of chlorfenapyr further promotes its progress and sensible application for pest management.