Calculation of needed medicine

[Dr. Z]

I wonder how the game calculates the amount of medicine needed to treat a injured person. I tried to figure it out by observation, but it neither depends on the amount of different wounds nor the number of bodyparts injured and I'm running out of ideas. Someone who knows this?

[Endoric]

I would like to add to this question.  While the medical skill determines success, quality and failure of treatment does it reduce the amount of medicine required?