RT Journal Article SR Electronic T1 THE RATIO OF THE TOXICITY OF ACETANILID TO ITS ANTIPYRETIC ACTIVITY IN RATS JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 346 OP 351 VO 54 IS 3 A1 PAUL K. SMITH A1 W. E. HAMBOURGER YR 1935 UL http://jpet.aspetjournals.org/content/54/3/346.abstract AB In rats fevered by yeast injections, a dose of 12.5 mgm. per kilogram of acetanilid produces an average fall in temperature of 0.6°C., while smaller doses are without significant effect and larger doses produced greater effects. Twelve and one-half milligrams per kilogram has been taken to the minimal therapeutic dose for rats. In normal animals, 50 mgm. per kilogram of acetanilid produces a significant decrease in temperature, similar to the fall produced in fevered animals by 12.5 mgm. per kilogram. The lowering of the temperature of the normal animal may be considered an early undesirable effect. The dose fatal to 50 per cent of the rats is 800 mgm. per kilogram. A therapeutic ratio of 64:1 for the antipyretic effect of acetanilid in rats has been obtained.