Coca tea and leaves are recommended to prevent altitude sickness[a] and most hotels have a tea corner like this, with leaves, tea and a thermos of hot water. I never tried the leaves (reportedly they tasted very bitter), but I had some tea. The tea tasted like a very mild green tea, and I noticed no apparent effect of it myself, but others swear by it. The effect is supposedly similar to a strong espresso. The cocaine content of the leaves are around .25% and .77%[b], which means that you are far from the concentrations required to get high.