Structural Biochemistry, Cocaine

Cocaine

(Image: Ahchow, CC BY-SA 3.0)

Cocaine (benzoylmethylecgonine) is a crystalline tropane alkaloid that is a central nervous system stimulant, appetite suppressant, and topical anesthetic. Cocaine is derived from coca plants and is a pearly, white powder in its most pure form. The drug was used as an anesthetic in the past but has now been replaced other synthetic anesthetics such as benzocaine. Today, cocaine is mainly used as a recreational drug and is highly addictive because of the way it affect’s the brains reward pathways.

Routes of Administration

Cocaine can be dissolved in water and injected, snorted in the hydrochloride salt form, smoked as a rock crystal, or injected vaginally or anally with a suppository. When snorting cocaine, the drug travels through the nose and is absorbed into the bloodstream via nasal tissues. To inject cocaine, users first mix the drug with water and then inject into the blood stream with a needle. This method carries risk of HIV/ AIDS from the potential of shared needles. Smoking cocaine involves processing the drug into a rock crystal form. The rock crystals are then heated so that the vapors will be inhaled. Upon inhalation, cocaine enters the lungs and is absorbed into the blood stream. An oral syringe is used to inject cocaine anally and vaginally. The drug is dissolved in water, inserted into the syringe, and then taken up through the membranous lining of the anal or vaginal walls.

Appearance

When speaking of purity, cocaine are usually white and pearly. Cocaine such as ones known as cocaine hydrochloride appears in powder as salt. Cocaine that are sold at street markets are often cut with various powdery fillers to increase its weight; thus, making the cost of cocaine much more expensive. The substances most often used in this process are baking soda; sugars, such as lactose and dextrose; and local anesthetics, such as lidocaine and benzocaine. Substances such as benzocaine add to cocaine's numbing effect on mucous membranes. In all, cut cocaine are usually, white, ivory, or pinkish powder.

The preparation method, presence of impurities, and where the cocaine originally came from are all very important when it comes to determining the color of "crack" cocaine. However, the colors of "crack" cocaine are often range from white to a yellowish cream to a light brown. Also, its texture will vary upon the way they cut the cocaine, origin and processing of the powdered cocaine, and the method of converting the base. Cocaine are sometimes crumbly in texture, sometimes extremely oily, powdery, and almost similar to crystals in nature.

Forms of Cocaine

There are many forms of cocaine. One such form is salt. Cocaine is a weakly alkaline compound also known as an "alkaloid"; hence, can combine with acidic compounds to form various salts. Although the sulfate (-SO4) and the nitrate (-NO3) are commonly seen, the hydrochloride (HCl) salt of cocaine is mostly encountered. Salts of different properties will dissolve and interact differently in various solvents. For example, the hydrochloride (HCl) salt is polar in character and is quite soluble in water. Another form of cocaine is basic. As opposed to the salt form, the term "freebase" is referred to as the base form of cocaine. Unlike hydrochloride salt, any cocaine base form is insoluble in water. Thus, smoking freebase cocaine has the an added effect of releasing methylecgonidine into the user's system due to the pyrolysis of the substances, which cause serious problems such as lung tissue and liver tissue infection. It is also known that through the technique of liquid-liquid extraction, pure cocaine can be prepare by neutralizing its compounding salt with an alkaline solution followed by a precipitation to a non-polar basic cocaine.

In addition, crack cocaine is a lower purity form of free-base cocaine. Crack cocaine is usually produced by neutralization of cocaine hydrochloride with a solution of baking soda (sodium bicarbonate, NaHCO3) and water, which in the end produces a very rough/hard/brittle, ivory to brown colored, amorphous material that contains sodium carbonate, entrapped water, and other by-products as the main impurities. Using "freebase" and "crack" forms of cocaine are easy because they vaporize smoothly. However, cocaine hydrochloride does not vaporize as easily because high temperature of about 197°C is needed. In the end, despite the forms of cocaine, smoking or vaporizing cocaine and inhaling it into the lungs produces a sense of "high" feeling and it can be very addicting as more cocaine are taken.

Effects on the Body

Cocaine highs generally last 10-30 minutes. The faster cocaine travels through the bloodstream and reaches the brain, the more intense the high will be. Upon taking cocaine, users experience euphoria and energy, including increased heart rate and blood pressure. The risks of cocaine are heart attack, stroke, seizure, abdominal pain, respiratory failure, nausea, and death. Because users often combine cocaine with other psychoactive drugs, the risk of sudden death is greatly increased. Cocaine is often combined with alcohol intake. Researchers have found that the liver combines cocaine and alcohol to produce cocaethylene which increases cocaine’s euphoric effect but also increased the risk of sudden death.
Cocaine increases the levels of dopamine in the brain. Dopamine is associated with pleasure and movement. Cocaine prevents dopamine from being recycled, causing the neurotransmitter to build up and continually amplify the message. The euphoric feelings are attributed to the continual build up of dopamine. Cocaine abuse occurs when long time users change the brain’s reward system.
Cocaine constricts blood vessels, dilates pupils, increased heart rate and temperature, headache, abdominal pain, and nausea. Intranasal use of cocaine may lead to loss of the sense of smell, nosebleeds, and a runny nose. Addicts often experience irritability, restlessness, and anxiety between binges. Hallucinations and paranoia are also common.

Drug Abuse and Addiction

Drug takers use cocaine, also known as crack or coke as a recreational drug. Cocaine is a more high priced way of getting high compared to that of marijuana. Also known as the “caviar of street drugs,” cocaine is known to be mystique, giving users alertness and energetic feelings. In addition, drug users often drink alcohol while under the influence of cocaine. Users feel more alert and aware while feeling the effects of alcohol minimally. The tolerance of taking the drug becomes increasingly higher as users ingest the drug more often. Since cocaine triggers different areas in the brain and put users on a good high, it may lead to addiction. As cocaine gets used regularly, addiction leads to physical and psychological problems and even death. Drug users may become highly dependent on the drug and when they are inaccessible to cocaine, feelings of withdrawal become present. Side effects may include fatigue, depression, anxiety, aches and pain.

References

http://drugabuse.gov/drugpages/cocaine.html
http://drugabuse.gov/infofacts/cocaine.html
http://en.wikipedia.org/wiki/Cocaine#Suppository

"Cocaine Use." WEBMD. WEBMD LLC. Web. 18 Nov 2012. <http://www.webmd.com/mental-health/cocaine-use-and-its-effects>.

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