Toxicological characteristics of neonicotinoids

In the article on the basis of own researches and analysis of relevant foreign and internal publications the authors present main issues, relating to the neonicotinoid toxicology. Neonicotinoids are known to be derived from 6-chlornicotinilic acid and at present they have been registered in 91 countries for applying for 60 kinds of crops. In Russia, more than 50 preparations produced on the basis of five active ingredients such as imidacloprid, thiacloprid, acetamiprid, clothianidin and thiamethoxam have been registered. Chemically, neonicotinoids are divided into two groups - nitroso-compounds (imidacloprid, dinotefuran, clothianidin) and cyanic ones (acetamiprid, thiacloprid). Neonicotinoids get into an organism mainly by feed, water, and through the skin. Imidacloprid and thiacloprid are rapidly absorbed from the stomach and intestines and spread throughout the body via bloodstream and lymph being accumulated in the skin keratins, internal organs, muscles, lymph nodes and brain. Imidacloprid and thiacloprid are able to penetrate through the placental and blood-brain barriers. Neonicotinoids are the neurotropic toxins therefore neonicotinoids toxicodynamics is similar to the nicotine effect. The two-phase nature of the action is manifested by the depolarization of ganglion neurons membrane - the first phase called as excitation, which gives way to the second phase - oppression. The pathogenesis of intoxication manifests mainly by the neurotoxic effects due to the development of tissue hypoxia with the development of toxic encephalopathy, hepatopathy and nephropathy. The clinical picture presents central cholinergic, extrapyramidal, peripheral nicotinoid syndrome as well as a peripheral adrenergic syndrome. At the neonicotinoid intoxication along with methods of detoxification therapy, either the injections of intravenous anticonvulsants and 5% solution of unitiol at a dose of 0.025 g/kg. as method of pathogenic therapy are recommended.