Some Pharmacological Characteristics of Bacitracin.

Abstract

The acute, intraperit. toxicity of bacitracin concentrates was greater in rats than in mice. The subcut. LD50 in mice was 4-7 times the intraperit. LD50. Lethal results were produced only with immense oral doses. Damage to the renal tubules, with tubular necrosis after very large doses, was observed in mice whereas in rats there was little kidney involvement. The toxicity of bacitracin, as measured by the LD50, appeared to be independent of the antibiotic activity. Concentrates of the antibiotic contained a minute amt. of an histamine-like substance which was not responsible for the definite depressor effect caused by the intraven. injn. of 10 mg. (300 units) per kg. into the dog.