1. I flew into Cuzco 20 yrs ago - on the way to Machu Picchu
They gave us coca-tea before we even got off the plane. I thought it tasted nasty and didn't drink it. Spouse drank it. They gave us more at the luggage collection area, at the taxi kiosk, and as we got to the hotel. Each time I refused, spouse drank it.....
I spent 3 miserable days in the throes of altitude sickness w/ the hotel doctor coming every 2-4 hrs. Spouse checked out surrounding sites.
Bottom line - drink the tea when they tell you to.