Cocaine's effects: Highs and harms

Cocaine burst back onto the American scene in the '70s as the "champagne of drugs": expensive, with high status. At the time, no one knew of its inherent dangers, and according to the Drug Enforcement Administration, as the price dropped over the next decade, nearly 6 million Americans used cocaine on a regular basis.

The high of a small amount of cocaine has been described as completely euphoric, producing a physical lightness and a boost of self-confidence that can leave a user begging for more. The intensity and length of the high depends on the method of ingestion: snorting a powdered form or rubbing it into the gums, liquefying it and "shooting up" intravenously or smoking a base form known as crack.

The National Institute on Drug Abuse says that snorting a line of cocaine produces a slow-building high that lasts 15 to 30 minutes. Smoking crack speeds up the rush, but it fizzles out even faster, within five or 10 minutes. Injecting provides the fastest high, followed by an equally spectacular decline.

The limited high is often what propels people to increase the dose or frequency of use, and that can be especially dangerous. Bodily reactions to any amount of the drug include dilated pupils and constricted blood vessels, with increased heart rate, blood pressure and temperature. Tremors, muscle spasms, panic and paranoia can set in with larger amounts of cocaine, along with headaches, seizures, stomach pain and nausea.

Although prescription opioid and heroin deaths in the US far outnumber those from cocaine, there was a 1.6-fold rise in deaths from cocaine between 2010 and 2015.

According to the National Survey on Drug Use and Health, there are about a million and a half Americans using cocaine right now; that number has stayed relatively constant since 2009. Not surprisingly, young people ages 18 to 25 use cocaine more than any other group.

Globally, the number of cocaine users has stayed stable between 1998 and 2014, largely due to a decline in production. But that doesn't mean the number is low. According to the World Drug Report, there were 17 million people around the world using cocaine in 2015.

Just how does cocaine cause addiction? By changing the brain.

Cocaine creates a euphoric high by flooding the brain with neurochemicals such as dopamine, serotonin and norepinephrine, some of the body's main pleasure chemicals. It blocks them from being absorbed, creating a chemical buildup in the reward center of the brain. The result: a rush of energy, alertness and high-flying mood.

Being rewarded is additive, so users return for another hit. Studies show that as the brain is exposed to more and more cocaine, its reward center adapts, becoming less receptive to natural positives such as food or affection.

That's just one reason for cocaine's seductive leverage. It also affects the way the brain responds to stress and makes choices. Animal studies suggest that the need for cocaine is increased by stress: The more cocaine animals were given, the more stress they felt and the more they wanted cocaine.

Research in animals and humans also shows that the drug reduces functioning in the orbitofrontal cortex, which controls decision-making abilities. In fact, studies of people with long-term cocaine addiction show reduced gray matter in the executive area of the brain as well as in the hippocampus, the area responsible for learning and memory.

To make matters worse, tolerance to the drug develops over time, so more cocaine is needed to create a high or reduce stress.

There is no "safe" level of cocaine use. There's no way to tell whether you'll become addicted, physically or psychologically, from one snort or more. In fact, recent studies in mice, whose brain reward system is similar to humans', show that a single dose can cause addictive behavior.

Long-term cocaine use can do a lot of damage to the body. Snorting it leads to nosebleeds, a perpetual sniff and a total loss of smell. Regular use can lead to nasal perforation. Smoking crack inflames asthma and can permanently harm the lungs.

Reduced blood flow in the intestines caused by cocaine can lead to ulcers and perforations. Appetite loss is common, and many chronic users are severely underweight and malnourished.

An increase in stroke risk is a well-known side effect of heavy cocaine use, even in the young and otherwise healthy. Seizures in the brain are possible, as is sudden violent or psychotic behavior.

Cardiovascular risk is high. Death from cocaine use is often via cardiac arrest, even among 20-somethings with no history of heart disease. That's because cocaine increases heart rate and blood pressure while constricting arteries, blocking the flow of blood to the heart.

Other dangers include an enlarged, inflamed heart or potentially deadly arrhythmia, an abnormal heart rhythm.

Unfortunately, there are no FDA-approved medications available to treat cocaine addiction. Cognitive behavioral therapy, a form of psychological treatment, or community recovery groups such as Cocaine Anonymous can be effective and are offered in both residential and outpatient settings.

According to the National Institute on Drug Abuse, clinical trials are underway for a number of medications. Some target neurotransmitters in the brain such as serotonin or the receptor site for dopamine, or they look at the impact of variants in our genes. There is even a vaccine for cocaine in the works.