Chronic toxicity of pyrazolones: the problem of nitrosation.

Article date: April 1980

By: M Kramer, in Volume 10, Issue S2, pages 313S-317S

1 During 6‐month oral toxicity studies of dipyrone in rats and dogs, there was an increase in the number of reticulocytes and Heinz bodies at the highest dose, and a slight haemosiderosis was induced. 2 Similar results were obtained after parenteral administration (intravenously and subcutaneously). 3 These studies fail to contribute to the knowledge of the mechanism of allergic reactions in man. 4 In vitro studies in conditions imitating the physiological environment, show to what extent nitrosation of dipyrone takes place. 5 Subsequent toxicological investigations with the two reaction compounds, or the nitrosation product itself, are powerful instruments to show whether the nitrosamine or nitrosamide formed is dangerous. 6 In the case of pyrazolones, only aminopyrine forms a carcinogenic nitrosamine.

DOI: 10.1111/j.1365-2125.1980.tb01815.x

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