Cocaine 
Cocaine abuse and addiction continue to plague our Nation. Today, about one in six Americans (15 percent in 2007) has tried cocaine by the age of 30, and 7 percent have tried it by their senior year of high school. But recent discoveries about the inner workings of the brain and the damaging effects of cocaine offer us unprecedented opportunities for addressing this persistent public health problem.
Genetic studies are providing critical information about the hereditary influences on the risk of addiction to psychoactive substances, including cocaine. Moreover, sophisticated imaging technologies have allowed scientists to visualize the brain changes that result from chronic drug exposure or that happen when an addicted person is exposed to drug-associated "cues" that can trigger craving and lead to relapse. By mapping the genetic factors and brain regions responsible for the multiple effects of cocaine, these new technologies can help us identify new targets for treating cocaine addiction.
Cocaine is a powerfully addictive stimulant drug. The powdered hydrochloride salt form of cocaine can be snorted or dissolved in water and then injected. Crack is the street name given to the form of cocaine that has been processed to make a rock crystal, which, when heated, produces vapors that are smoked. The term “crack” refers to the crackling sound produced by the rock as it is heated.
How Is Cocaine Abused?
Three routes of administration are commonly used for cocaine: snorting, injecting, and smoking. Snorting is the process of inhaling cocaine powder through the nose, where it is absorbed into the bloodstream through the nasal tissues. Injecting is the use of a needle to insert the drug directly into the bloodstream. Smoking involves inhaling cocaine vapor or smoke into the lungs, where absorption into the bloodstream is as rapid as by injection. All three methods of cocaine abuse can lead to addiction and other severe health problems, including increasing the risk of contracting HIV and other infectious diseases.
The intensity and duration of cocaine’s effects—which include increased energy, reduced fatigue, and mental alertness—depend on the route of drug administration. The faster cocaine is absorbed into the bloodstream and delivered to the brain, the more intense the high. .jpg)
Injecting or smoking 
cocaine produces a quicker, stronger high than snorting. On the other hand, faster absorption usually means shorter duration of action: the high from snorting cocaine may last 15 to 30 minutes, but the high from smoking may last only 5 to 10 minutes. In order to sustain the high, a cocaine abuser has to administer the drug again. For this reason, cocaine is sometimes abused in binges—taken repeatedly within a relatively short period of time, at increasingly higher doses.
How Does Cocaine Affect the Brain?
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 
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. Cocaethylene is associated with a greater risk of sudden death than cocaine alone.
What Treatment Options Exist?
Behavioral interventions—particularly, cognitive-behavioral therapy—have been shown to be effective for decreasing cocaine use and preventing relapse. Treatment must be tailored to the individual patient’s needs in order to optimize outcomes—this often involves a combination of treatment, social supports, and other services.
Currently, there are no FDA-approved medications for treating cocaine addiction; thus, developing a medication to treat cocaine and other forms of addiction remains one of NIDA’s top research priorities. Researchers are seeking to develop medications that help alleviate the severe craving associated with cocaine addiction, as well as medications that counteract cocaine-related relapse triggers, such as stress. Several compounds are currently being investigated for their safety and efficacy, including a vaccine that would sequester cocaine in the bloodstream and prevent it from reaching the brain. Current research suggests that while medications are effective in treating addiction, combining them with a comprehensive behavioral therapy program is the most effective method to reduce drug use in the long term.
How Widespread Is Cocaine Abuse? 
Monitoring the Future Survey*
According to the 2008 Monitoring the Future survey—a national survey of 8th-, 10th-, and 12th-graders—cocaine use among students did not change significantly, though it remained at unacceptably high levels: 3.0 percent of 8th-graders, 4.5 percent of 10th-graders, and 7.2 percent of 12th-graders have tried cocaine; 0.8 percent of 8th-graders, 1.2 percent of 10th-graders, and 1.9 percent of 12th-graders were current (past-month) cocaine users. Crack cocaine use, which has been steadily declining since 1990, showed a significant decrease among 12th-graders in the past year.
Use of Cocaine in Any Form by Students
2008 Monitoring the Future Survey
