Yes, the coca tea was pretty necessary .. even with that I had my standard high-altitude blackout. Some Americanos thought it would be cool to take some of those coca leaves home, which is(or was) highly illegal. One couple on our tour was detained at the Lima airport as we were leaving .. wonder what ever became of them.
The world is so full of wonderful places and things to see .. if only there were enough $ and time to do it all! (starting in the USA, of course!)