The patient was prescribed Vicasol (Menadione) several days before the elective surgery for peptic ulcer disease of the stomach. What is the mechanism of action of this drug?

Answer options

1. Suppresses platelet aggregation
2. Suppresses fibrinolysis
3. Decreases vascular permeability
4. Binds free calcium ions, removing calcium from coagulation reaction
5. Increases blood coagulability via intensified prothrombin synthesis