The remedy for exhaustion (Vampyr)

Hello. I have a few questions:
1)What ingredients are needed for a means of fatigue? Who then give?
2) how to treat patients?
3)When people ask about health there is 2 options-to give medication and to give. Giving the medicine-always unavailable-why?
4) When walking around the city if there are opportunities to bypass the sentinel ,so they don't notice? (Except in stealth mode).
5) Ingredients for drugs to go around the city?
Thank you.