Reactions of 2-Methyl-1,4-Naphthoquinone (Menadione) with Whole Blood and Plasma in vitro

Abstract

Summary

When added to whole, unlaked blood, menadione causes a marked methemoglobin formation, and the drug is rapidly converted to some other substance (or substances). Assays with vitamin K-deficient chicks showed that these reactions cause a marked loss in the antihemorrhagic activity of the menadione. Vitamin K_1, unlike menadione, does not produce methemoglobin under comparable conditions, and the vitamin is remarkably stable in whole blood.