title: Toxicology of selected pesticides, drugs, and chemicals. Pyrethrin and pyrethroid insecticides.
abstract: Pyrethroids have a wide spectrum of insecticidal potency, vertebrate toxicity, and environmental stability. The exceptionally high selectivity ratios of pyrethrins and pyrethroids have resulted in their use for insect control in numerous formulations. A primary effect of pyrethroids is to slow the closing of the sodium activation gate in nerve cells. All pyrethroids have essentially the same basic mechanism of action on voltage-dependent sodium channels but differ in the magnitude of effect. Based on clinical signs, electrophysiologic responses, and chemical structure, pyrethroids can be classified as Type I or Type II. Inhibition of the GABAA receptor appears to be an additional mechanism of Type II pyrethroids. Clinical signs in small animals during a pyrethroid toxicosis vary but are generally attributable to neural dysfunction. Treatment consists of decontamination procedures and application of appropriate symptomatic care, including control of seizures if necessary.
authors.affiliation: Department of Pathology, Duke University Medical Center, Durham, North Carolina.
authors.forename: W M
authors.initials: WM
authors.lastname: Valentine
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000139:chemically induced*; D002415:Cats; D004283:Dog Diseases / Q000139:chemically induced*; D004285:Dogs; D011722:Pyrethrins / Q000506:poisoning*
chemical_list: D011722:Pyrethrins