Pharmacological and toxicological studies on domiodol, a new mucolytic agent and expectorant

The efficacy and toxicity of a compound containing organically bound iodine, 4-hydroxymethyl-2-indomethyl-2,3-dioxolane (domiodol), were evaluated. After oral and intravenous administration domiodol increased respiratory tract excretion indirectly measured on the basis of bronchial secretion in rats. Based on Kasé's method for quantitatively collecting respiratory tract fluid from rabbits, oral domiodol at the dose of 50-200 mg/kg induced a dose-related increase in respiratory tract fluid. In addition, oral domiodol (50 and 100 mg/kg) significantly reduced the viscosity of sputum collected quantitatively from rabbits with subacute bronchitis induced by long-term exposure to SO2 gas; the percentage decrease in viscosity was statistically correlated with the content of dry matter, protein and polysaccharides in the sputum. Domiodol had a marked cilio-excitatory effect, but did not affect experimental asthma in guinea-pigs or the respiratory resistance of anesthetized dogs. Subacute toxicity of the substance was investigated in rats. In serum biochemistry tests mean triglycerides were reduced in both sexes at dose levels higher than 32 mg/kg. Changes of T3 levels and a slight increase in thyroid weight accompanied by minimal histological alterations were observed in rats given high doses of domiodol. The majority of the changes observed were reversible after withdrawal of domiodol.