EFFECTS OF SODIUM BICARBONATE ON THE ANTIPYRETIC ACTION AND TOXICITY OF ACETANILID

¹ From the Department of Pharmacology and Toxicology, Yale University

Sodium bicarbonate in a molecular ratio of two to one is markedly antagonistic to the acute toxic effects of acetanilid. Smaller and larger ratios are less effective.

The 50 per cent fatal dose in rats of acetanilid plus sodium bicarbonate in a molecular ratio of two to one is approximately 1000 mgm. per kilogram. Addition of bicarbonate to the 50 per cent fatal dose of acetanilid reduced the fatalities to 20 per cent.

In rats fevered by yeast injections, sodium bicarbonate in a molecular ratio of two to one did not significantly affect the antipyretic effect produced by 12.5 mgm. per kilogram of acetanilid.

In normal animals sodium bicarbonate does not significantly affect the fall in temperature produced by 400 mgm. per kilogram of acetanilid, indicating that the rate and extent of absorption are not appreciably altered.

The administration of 400 mgm. of acetanilid per kilogram plus 500 mgm. per kilogram of sodium bicarbonate to normal rats daily for twelve weeks produced a significant retardation of growth, slightly less than that produced by acetanilid alone.

The addition of bicarbonate did not prevent the changes in the hemoglobin concentration, the erythrocyte and the reticulocyte counts produced by 400 mgm. per kilogram of acetanilid given daily.