Cocaine is found in the leaves of the Erythroxylon coca plant, a large shrub indigenous to South America. The compound is extracted from the leaves and is then processed into either paste, powder, or freebase form. The paste is the most rudimentary, unrefined form. Additional processing of the paste by adding hydrochloric acid produces cocaine powder (cocaine hydrochloride). Cocaine powder is often administered via nasal insufflation (i.e., snorting). Freebase cocaine is the pure cocaine base released from cocaine hydrochloride by further separation using simple chemicals such as ether or sodium hydroxide. This freebase cocaine is easily absorbed into the membranes of the relatively alkaline environment of the body. The well-known "crack" cocaine is simply baking soda and water mixed with the base to create a solid form of freebase cocaine which is immediately and completely absorbed by the body when smoked. The most common routes of administration for cocaine are smoking and snorting although the intravenous route is also used and is often preferred by those who also inject other drugs, such as opiates.
In humans, cocaine produces an elevation in mood and a sense of increased energy and alertness. This can include an improvement in concentration and attention, a reduction in the sense of fatigue and performance decrement caused by sleep deprivation, appetite suppression, and an increase in libido. The toxic effects of high doses of cocaine include delirium, seizures, stupor, cardiac arrhythmias , and coma. Seizures can result in sustained convulsions that stop breathing.
The most prominent pharmacological effect of cocaine is to block the reuptake of dopamine back into the presynaptic terminal once it has been released from a neuron terminal, resulting in increased levels of dopamine at its synapses in the brain. The specific uptake site for dopamine has been identified and cocaine's...