Cocaine is a synthetically prepared stimulant that is derived from the coca plant. The purified chemical known as cocaine hydrochloride was discovered more than a century ago and was widely used in the early 1900s in tonics to cure multiple illnesses. These days, the drug is usually used in a powder form, either snorted or injected or smoked in the form of crack cocaine. Cocaine is a highly addictive stimulant, and many users need the help of cocaine rehabilitation centers to get clean and sober.