Menadione (Vitamin K3)

Menadione is fat-soluble synthetic vitamin K3. It can cause hemolysis in G-6-PD deficient individuals. In severe hepatic disease, large doses of menadione can further depress liver function. Menadione is not used to prevent haemorrhagic disease of the newborn as it can cause kernicterus, instead phytonadione is used. Phytonadione is also the drug of choice to overcome the toxic effects of warfarin as it acts rapidly.