Cocaine
Cocaine is a central nervous system stimulant and tropane alkaloid derived primarily from the leaves of two coca species native to South America: Erythroxylum coca and E. novogranatense. Coca leaves are processed into cocaine paste, a crude mix of coca alkaloids which cocaine base is isolated and converted to cocaine hydrochloride, commonly known as "cocaine". Cocaine was once a standard topical medication as a local anesthetic with intrinsic vasoconstrictor activity, but its high abuse potential, adverse effects, and cost have limited its use and led to its replacement by other medicines. "Cocaine and its combinations" are formally excluded from the WHO Model List of Essential Medicines.
Street cocaine is commonly snorted, injected, or smoked as crack cocaine, with effects lasting up to 90 minutes depending on the route.