Why don’t we sell acetaminophen capsules pre-mixed with N-acetylcysteine?  That’s the antidote for acetaminophen overdose.  It would probably eliminate most of the fulminant hepatic failure from acetaminophen overdose.

Why don’t we add 5%-10% w/w Vitamin K to warfarin?  Regular dosing of this combination would lock in an INR solid, probably within 0.1 units of targeted value.  It could eliminate the need to test INR’s so much, and may eliminate warfarin-related bleeds.

Why not?