How Does Cocaine Affect the Brain?

Cocaine

Effects

Cocaine is a strong central nervous system stimulant that increases levels of dopamine, a brain chemical (or neurotransmitter) associated with pleasure and movement, in the brain’s reward circuit. Certain brain cells, or neurons, use dopamine to communicate. Normally, dopamine is released by a neuron in response to a pleasurable signal (e.g., the smell of good food), and then recycled back into the cell that released it, thus shutting off the signal between neurons. Cocaine acts by preventing the dopamine from being recycled, causing excessive amounts of the neurotransmitter to build up, amplifying the message to and response of the receiving neuron, and ultimately disrupting normal communication. It is this excess of dopamine that is responsible for cocaine’s euphoric effects. With repeated use, cocaine can cause long-term changes in the brain’s reward system and in other brain systems as well, which may eventually lead to addiction. With repeated use, tolerance to the cocaine high also often develops. Many cocaine abusers report that they seek but fail to achieve as much pleasure as they did from their first exposure. Some users will increase their dose in an attempt to intensify and prolong the euphoria, but this can also increase the risk of adverse psychological or physiological effects.

What Adverse Effects Does Cocaine Have on Health?

Abusing cocaine has a variety of adverse effects on the body. For example, cocaine constricts blood vessels, dilates pupils, and increases body temperature, heart rate, and blood pressure. It can also cause headaches and gastrointestinal complications such as abdominal pain and nausea. Because cocaine tends to decrease appetite, chronic users can become malnourished as well.

Different methods of taking cocaine can produce different adverse effects. Regular intranasal use (snorting) of cocaine, for example, can lead to loss of the sense of smell; nosebleeds; problems with swallowing; hoarseness; and a chronically runny nose. Ingesting cocaine can cause severe bowel gangrene as a result of reduced blood flow. Injecting cocaine can bring about severe allergic reactions and increased risk for contracting HIV and other blood-borne diseases. Binge-patterned cocaine use may lead to irritability, restlessness, and anxiety. Cocaine abusers can also experience severe paranoia—a temporary state of full-blown paranoid psychosis—in which they lose touch with reality and experience auditory hallucinations.

Regardless of the route or frequency of use, cocaine abusers can experience acute cardiovascular or cerebrovascular emergencies, such as a heart attack or stroke, which may cause sudden death. Cocaine-related deaths are often a result of cardiac arrest or seizure followed by respiratory arrest.

Added Danger: Cocaethylene - when cocaine and alcohol are consumed together, the body forms a unique cocaine metabolite named cocaethylene. It is unique because it is formed only during the combined ingestion of cocaine and alcohol. (The name “cocaethylene” is derived from the words “cocaine” and “ethyl alcohol.”) It is unique also because it is the first known example of the body forming a third drug following ingestion of two other drugs. It is not a natural alkaloid of the coca leaf, and is not found in street cocaine.

Polydrug use—use of more than one drug—is common among substance abusers. When people consume two or more psychoactive drugs together, such as cocaine and alcohol, they compound the danger each drug poses and unknowingly perform a complex chemical experiment within their bodies. Researchers have found that the human liver combines cocaine and alcohol to produce a third substance, cocaethylene that intensifies cocaine’s euphoric effects. Coca ethylene is associated with a greater risk of sudden death than cocaine alone.

Statistics and trends

Global cocaine use has remained stable at 0.3-0.4 per cent of the population aged 15-64 (between 13.2 million and 19.5 million users) but there have also been some shifts in its use, with a substantial decrease in the prevalence of cocaine use in North America and in some countries in South America and indications of increases in Oceania, Asia, Africa and some countries in South America.

In 2010, the regions with a high prevalence of cocaine use remained North America (1.6 per cent), Western and Central Europe (1.3 per cent) and Oceania (1.5-1.9 per cent) the latter effectively reflecting its use in Australia and New Zealand. While global estimates of cocaine use have remained stable at 0.3-0.4 per cent of the population aged 15-64 (between 13 million and 19.5 million users), a substantial decrease was reported in North America and some countries in South America, with the annual prevalence of cocaine use in North America decreasing from 1.9 per cent in 2009 to 1.6 per cent in 2010.
The current prevalence rate of cocaine is 0.1% in Kenya.

COURTESY OF NACADA-KENYA