Cocaine is an alkaloid ester extracted from the leaves of plants including coca. Cocaine is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake. Cocaine is addictive due to its effect on the reward pathway in the brain. After a short period of use, there is a high risk that dependence will occur. Its use also increases the risk of stroke, myocardial infarction, lung problems in those who smoke it, blood infections, and sudden cardiac death. Cocaine sold on the street is commonly mixed with local anesthetics, cornstarch, quinine, or sugar which can result in additional toxicity. Following repeated doses, a person may have decreased the ability to feel pleasure and be very physically tired. Cocaine acts by inhibiting the reuptake of serotonin, norepinephrine, and dopamine. This results in greater concentrations of these three neurotransmitters in the brain. It can easily cross the blood-brain barrier and may lead to the breakdown of the barrier.

Cocaethylene is the ethyl ester of benzoylecgonine. Cocaethylene is formed in the liver after concurrent use of cocaine and alcohol. Cocaethylene works by blocking the dopamine transporter on dopaminergic presynaptic nerve terminals in the brain. It increases dopamine synaptic content, provoking enhanced postsynaptic receptor stimulation, resulting in euphoria, reinforcement, and self-administration. Compared to cocaine, which is a methyl ether of benzoylecgonine, cocaethylene has three to five times larger half-life in plasma. Cocaethylene is associated with seizures, liver damage and compromised the functioning of the immune system. It carries an 18-25 fold increase in risk for immediate death compared to cocaine alone.

Benzoylecgonine can be found in medical products as a topical muscle relaxer, anesthetic or to relieve muscle pain. It is also a metabolite that is created in the liver after drug use, in particular, the use of cocaine, making it the main compound tested for cocaine use during drug screenings. The legality of this compound is in the grey area. Cocaine is a schedule II drug, but the metabolite is not the drug, it’s a by-product of its use. So detection of actual use is impossible, as its already a metabolite. But the use of cocaine and cocaine based drugs like crack is detected, through this compound. Benzoylecgonine is formed in the liver by the metabolism of cocaine, catalysed by carboxylesterases, and subsequently excreted in the urine. It can be found in the urine for considerably longer than the cocaine itself which is generally cleared out within 5 days