Oral and Parenteral Toxicity of Vitamin K 1,Phthiocol and 2 Methyl 1,4,Naphthoquinone

Abstract

Summary

The acute and chronic toxicity of Phthiocol, 2-methyl-1,4-naphthoquinone and vitamin K₁ was studied in mice, rats, and chicks. The oral L.D. 50 in mice was found to be approximately 0.2 g per kg for Phthiocol and 0.5 g per kg for 2-methyl-1,4-naphtho-quinone; no lethal effect could be produced by doses up to 25 g per kg of vitamin K₁. In the chronic experiments in rats, daily feeding over a period of 30 consecutive days of 0.35 g per kg of Phthiocol, and 0.5 g per kg of 2-methyl-1,4-naphthoquinone was toxic; doses of 0.1 g per kg of Phthiocol and 0.35 g per kg of 2-methyl-1,4-naphthoquinone produced a marked fall of the erythrocyte count and hemoglobin. No such effects were observed following vitamin K₁ administration. In the abdominal cavity of animals sacrificed 10 days after an intraperitoneal injection of vitamin K₁ considerable amounts of an oily suspension could be observed, indicating an extremely slow rate of absorption of vitamin K₁.