TOXICOLOGICAL EVALUATION OF INDOMETHACIN AS A RISK FACTOR FOR WORKERS’ HEALTH

Abstract

Introduction. The toxicity of indomethacin was studied for its hygienic regulation. Material and methods. The toxic properties of indomethacin in the experiments on out-bred and linear mice, rats, Guinea pigs and rabbits contained in standard vivarium conditions and quarantined have been studied. In the experiments, various modes (single, repeated, chronic) and ways of exposure (intragastric, inhalation, epicutaneous) were modeled. The average lethal dose (LD50) of Indomethacin and the threshold of a single acute action (Limac) were determined; irritant effect on the skin and mucous membranes, cumulative and allergenic activity were revealed. In subacute and chronic intake to the body, the main target organs were determined on the based of the results of biochemical and hematological studies. Results. DL50 for male rats, females and male mice, when introduced into the stomach, were have been established to be 20, 15 and 25.6 mg/kg respectively. It refers to the substances of hazard class 2. DL50 in the intraperitoneal introduction for the rats accounted for 13.8 mg/kg, for Guinea pigs - 500 mg/kg. The clinical picture of acute poisoning in mice and rats was characterized by low mobility, decreasing breathing, ataxia, muscle relaxation, anorexia, diarrhea, ulceration with the perforation of the intestines, and the death on the 2-4th days after the poisoning. In the experiments on Guinea pigs, the ulcerogenic effect was not detected. Local irritant effect on the skin and mucous membranes of the eyes was not revealed. It has a marked skin-resorptive action causing ulcerogenic effect and the death of the animals after 6 applications. The introduction of verospiron to the rats in a dose of 25 mg/kg simultaneously with the application of indomethacin ointment on the skin prevented the ulcer development in the gastrointestinal tract and the death of the animals. No sensitizing effect was detected. It has an average cumulative ability: the cumulation coefficient amounted to 2.6. In a subacute experiment, there was a decrease in the body temperature and summation-threshold index, an increase in the vertical motor activity and a threshold of pain sensitivity. During the study of blood serum an increase in AcAt activity, a rise of chlorides in the blood serum and their decrease in the urine, and an increase in the number of erythrocytes and hemoglobin in peripheral blood were revealed. In the pathomorphological study, there was an increase in the coefficients of liver mass and ulceration of the stomach and intestines. The threshold of acute inhalation action accounted for 0.52 mg/m3 (by the reduction of the summation-threshold index and the content of sodium and chlorides in the urine). Conclusion. The maximum permissible concentration of indomethacin in the air of the working area was of 0.05 mg/m3 with the mark “special protection of the skin and eyes”, hazard class 1, aerosol.