Coca tea is a herbal tea made from the leaves of the Coca plant. Hot water is poured over the leaves and allowed to steep. Native to Peru and Bolivia this Tea along with oxygen are given to those people suffering from altitude sickness.
But BEWARE this Coca Plant contains alkaloids which when extracted chemically is the base for cocaine. (The coca alkaloid content of coca tea is such that the consumption of one cup of coca tea can cause a positive result on a drug test for cocaine). So don't drink it in excess.