What is cocaine?

C

ocaine is a powerfully addictive stimulant that directly

affects the brain. Cocaine

has been labeled the drug of the

1980s and ‘90s, because of its

extensive popularity and use during this period. However, cocaine

is not a new drug. In fact, it is

one of the oldest known drugs.

The pure chemical, cocaine

hydrochloride, has been an

abused substance for more than

100 years, and coca leaves, the

source of cocaine, have been

ingested for thousands of years.

Pure cocaine was first extracted from the leaf of the

Erythroxylon coca bush, which

grows primarily in Peru and

Bolivia, in the mid-19th century.

In the early 1900s, it became the

main stimulant drug used in most

of the tonics/elixirs that were

developed to treat a wide variety

of illnesses. Today, cocaine is a

Schedule II drug, meaning that it

has high potential for abuse, but

can be administered by a doctor

for legitimate medical uses, such

as a local anesthetic for some eye,

ear, and throat surgeries. 

There are basically two 

chemical forms of cocaine: 

the hydrochloride salt and the

“freebase.” The hydrochloride

salt, or powdered form of

cocaine, dissolves in water and,

when abused, can be taken intravenously (by vein) or intranasally

(in the nose). Freebase refers to a

compound that

has not been neutralized by an acid

to make the

hydrochloride

salt. The freebase

form of cocaine is

smokable.

Cocaine is

generally sold on

the street as a

fine, white, crystalline powder,

COCAINE

Abuse and Addiction

Cocaine abuse and addiction

continues to be a problem that

plagues our nation. In 1997, for

example, an estimated 1.5 million

Americans age 12 and older were

chronic cocaine users. Although this

is an improvement over the 1985

estimate of 5.7 million users, we still

have a substantial distance to go in

reducing the use of this addictive

stimulant. Science is helping. For

example, we now know more about

where and how cocaine acts in the

brain, including how the drug produces its pleasurable effects and why

it is so addictive. 

Through the use of sophisticated

technology, scientists can actually see

the dynamic changes that occur in

the brain as an individual takes the

drug. They can observe the different

brain changes that occur as a person

experiences the “rush,” the “high,”

and, finally, the craving of cocaine.

They can also identify parts of the

brain that become active when a

cocaine addict sees or hears environmental stimuli that trigger the craving for cocaine. Because these types

of studies pinpoint specific brain

regions, they are critical to identifying targets for developing medications to treat cocaine addiction. 

One of NIDA’s most important

goals is to translate what scientists

learn from research, in order to help

the public better understand drug

abuse and addiction, and to develop

more effective strategies for their

prevention and treatment. We hope

that this compilation of scientific

information on cocaine will help to

inform readers about the harmful

effects of cocaine abuse, and that it

will assist in prevention and treatment efforts.

Alan I. Leshner, Ph.D.

Director

National Institute on Drug Abuse

from the director

U.S. Department of Health and Human Services ● National Institutes of Health
known as “coke,” “C,” “snow,”

“flake,” or “blow.” Street dealers

generally dilute it with such inert

substances as cornstarch, talcum

powder, and/or sugar, or with

such active drugs as procaine (a

chemically-related local anesthetic) or with such other stimulants

as amphetamines. 

What is crack?

C

rack is the street name given

to the freebase form of

cocaine that has been

processed from the powdered

cocaine hydrochloride form to a

smokable substance. The term

“crack” refers to the crackling

sound heard when the mixture is

smoked. Crack cocaine is

processed with ammonia or sodium bicarbonate (baking soda)

and water, and heated to remove

the hydrochloride. 

Because crack is smoked, the

user experiences a high in less

than 10 seconds. This rather

immediate and euphoric effect is

one of the reasons that crack

became enormously popular in

the mid 1980s. Another reason is

that crack is inexpensive both to

produce and to buy.

What is the scope

of cocaine use in

the United States?

I

n 1997, an estimated 1.5 million Americans (0.7 percent of

those age 12 and older) were

current cocaine users, according

to the 1997 National Household

Survey on Drug Abuse

(NHSDA). This number has not

changed significantly since 1992,

although it is a dramatic decrease

from the 1985 peak of 5.7 million

cocaine users(3 percent of the

population). Based upon additional data sources that take into

account users underrepresented

in the NHSDA, the Office of

National Drug Control Policy

estimates the number of chronic

cocaine users at 3.6 million.

Adults 18 to 25 years old have

a higher rate of current cocaine

use than those in any other age

group. Overall, men have a higher

rate of current cocaine use than

do women. Also, according to the

1997 NHSDA, rates of current

cocaine use were 1.4 percent for

African Americans, 0.8 percent

for Hispanics, and 0.6 percent for

Caucasians. 

Crack cocaine remains a serious problem in the United States.

The NHSDA estimated the number of current crack users to be

about 604,000 in 1997, which

does not reflect any significant

change since 1988. 

The 1998 Monitoring the

Future Survey, which annually

surveys teen attitudes and recent

drug use, reports that lifetime

and past-year use of crack

increased among eighth graders

to its highest levels since 1991,

the first year data were available

for this grade. The percentage of

eighth graders reporting crack

use at least once in their lives

increased from 2.7 percent in

1997 to 3.2 percent in 1998. Pastyear use of crack also rose slightly among this group, although no

changes were found for other

grades. 

Data from the Drug Abuse

Warning Network (DAWN)

showed that cocaine-related

emergency room visits, after

increasing 78 percent between

1990 and 1994, remained level

between 1994 and 1996, with

152,433 cocaine-related episodes

reported in 1996. 

2 NIDA RESEARCH REPORT SERIES

Trends in 30-day prevalence of cocaine abuse among

eighth, tenth, and twelfth graders, 1991-1998

Source: Monitoring the Future Study, University of Michigan

Number of students

(Thousands)

12th grade

3.0

2.5

2.0

1.5

1.0

0.5

0.0 91 92 93 94 95 96 97 98

10th grade

8th grade
How is 

cocaine used?

T

he principal routes of

cocaine administration are

oral, intranasal, intravenous,

and inhalation. The slang terms

for these routes are, respectively,

“chewing,” “snorting,” “mainlining,” “injecting,” and “smoking”

(including freebase and crack

cocaine). Snorting is the process

of inhaling cocaine powder

through the nostrils, where it is

absorbed into the bloodstream

through the nasal tissues.

Injecting releases the drug directly into the bloodstream, and

heightens the intensity of its

effects. Smoking involves the

inhalation of cocaine vapor or

smoke into the lungs, where

absorption into the bloodstream

is as rapid as by injection. The

drug can also be rubbed onto

mucous tissues. Some users combine cocaine powder or crack

with heroin in a “speedball.”

Cocaine use ranges from

occasional use to repeated or

compulsive use, with a variety of

patterns between these extremes.

There is no safe way to use

cocaine. Any route of administration can lead to absorption of

toxic amounts of cocaine, leading

to acute cardiovascular or cerebrovascular emergencies that

could result in sudden death.

Repeated cocaine use by any

route of administration can produce addiction and other adverse

health consequences. 

How does cocaine

produce its effects? 

A

great amount of research

has been devoted to understanding the way cocaine

produces its pleasurable effects,

and the reasons it is so addictive.

One mechanism is through its

effects on structures deep in the

brain. Scientists have discovered

regions within the brain that,

when stimulated, produce feelings of pleasure. One neural system that appears to be most

affected by cocaine originates in a

region, located deep within the

brain, called the ventral tegmental

area (VTA). Nerve cells originating in the VTA extend to the

region of the brain known as the

nucleus accumbens, one of the

NIDA RESEARCH REPORT SERIES 3

Cocaine in the brain – In the normal communication process, dopamine is released by a neuron into

the synapse, where it can bind with dopamine receptors on neighboring neurons. Normally dopamine is

then recycled back into the transmitting neuron by a specialized protein called the dopamine transporter.

If cocaine is present, it attaches to the dopamine transporter and blocks the normal recycling process,

resulting in a build-up of dopamine in the synapse which contributes to the pleasurable effects of

cocaine.

Dopamine

transporter

functioning

normally

Dopamine

transporter

blocked by

cocaine

Cocaine

Dopamine receptors

Receiving Neuron

Transmitting

Neuron

Dopamine

packaged in vesicles
brain’s key pleasure centers. In

studies using animals, for example, all types of pleasurable stimuli, such as food, water, sex, and

many drugs of abuse, cause

increased activity in the nucleus

accumbens. 

Researchers have discovered

that, when a pleasurable event is

occurring, it is accompanied by a

large increase in the amounts of

dopamine released in the nucleus

accumbens by neurons originating

in the VTA. In the normal communication process, dopamine is

released by a neuron into the

synapse (the small gap between

two neurons), where it binds with

specialized proteins (called

dopamine receptors) on the

neighboring neuron, thereby

sending a signal to that neuron.

Drugs of abuse are able to interfere with this normal communication process. For example, scientists have discovered that cocaine

blocks the removal of dopamine

from the synapse, resulting in an

accumulation of dopamine. This

buildup of dopamine causes continuous stimulation of receiving

neurons, probably resulting in the

euphoria commonly reported by

cocaine abusers. 

As cocaine abuse continues,

tolerance often develops. This

means that higher doses and more

frequent use of cocaine are

required for the brain to register

the same level of pleasure experienced during initial use. Recent

studies have shown that, during

periods of abstinence from

cocaine use, the memory of the

euphoria associated with cocaine

use, or mere exposure to cues

associated with drug use, can trigger tremendous craving and

relapse to drug use, even after

long periods of abstinence.

What are 

the short-term

effects of 

cocaine use?

C

ocaine’s effects appear almost

immediately after a single

dose, and disappear within a

few minutes or hours. Taken in

small amounts (up to 100 mg),

cocaine usually makes the user

feel euphoric, energetic, talkative,

and mentally alert, especially to

the sensations of sight, sound,

and touch. It can also temporarily

decrease the need for food and

sleep. Some users find that the

drug helps them to perform simple physical and intellectual tasks

more quickly, while others can

experience the opposite effect.

The duration of cocaine’s

immediate euphoric effects

depends upon the route of administration. The faster the absorption, the more intense the high.

Also, the faster the absorption,

the shorter the duration of action.

The high from snorting is relatively slow in onset, and may last

15 to 30 minutes, while that from

smoking may last 5 to 10 minutes. 

The short-term physiological

effects of cocaine include constricted blood vessels; dilated

pupils; and increased temperature,

heart rate, and blood pressure.

Large amounts (several hundred

milligrams or more) intensify the

user’s high, but may also lead to

bizarre, erratic, and violent behavior. These users may experience

tremors, vertigo, muscle twitches,

paranoia, or, with repeated doses,

a toxic reaction closely resembling amphetamine poisoning.

Some users of cocaine report feelings of restlessness, irritability,

and anxiety. In rare instances,

sudden death can occur on the

first use of cocaine or unexpectedly thereafter. Cocaine-related

deaths are often a result of cardiac

arrest or seizures followed by respiratory arrest.

What are the 

long-term effects

of cocaine use?

C

ocaine is a powerfully addictive drug. Once having tried

cocaine, an individual may

have difficulty predicting or controlling the extent to which he or

she will continue to use the drug.

Cocaine’s stimulant and addictive

effects are thought to be primarily a result of its ability to inhibit

the reabsorption of dopamine by

4 NIDA RESEARCH REPORT SERIES

Short-term effects 

of cocaine

Increased energy

Decreased appetite

Mental alertness

Increased heart rate and

blood pressure

Constricted blood vessels

Increased temperature

Dilated pupils
nerve cells. Dopamine is released

as part of the brain’s reward system, and is either directly or indirectly involved in the addictive

properties of every major drug of

abuse.

An appreciable tolerance to

cocaine’s high may develop, with

many addicts reporting that they

seek but fail to achieve as much

pleasure as they did from their

first experience. Some users will

frequently increase their doses to

intensify and prolong the euphoric effects. While tolerance to the

high can occur, users can also

become more sensitive (sensitization) to cocaine’s anesthetic and

convulsant effects, without

increasing the dose taken. This

increased sensitivity may explain

some deaths occurring after

apparently low doses of cocaine.

Use of cocaine in a binge,

during which the drug is taken

repeatedly and at increasingly

high doses, leads to a state of

increasing irritability, restlessness, and paranoia. This may

result in a full-blown paranoid

psychosis, in which the individual

loses touch with reality and experiences auditory hallucinations.

What are 

the medical 

complications 

of cocaine abuse?

T

here are enormous medical

complications associated

with cocaine use. Some of

the most frequent complications

are cardiovascular effects, including disturbances in heart rhythm

and heart attacks; such respiratory effects as chest pain and respiratory failure; neurological

effects, including strokes, seizure,

and headaches; and gastrointestinal complications, including

abdominal pain and nausea.

Cocaine use has been linked

to many types of heart disease.

Cocaine has been found to trigger chaotic heart rhythms, called

ventricular fibrillation; accelerate

heartbeat and breathing; and

increase blood pressure and body

temperature. Physical symptoms

may include chest pain, nausea,

blurred vision, fever, muscle

spasms, convulsions and coma.

Different routes of cocaine

administration can produce different adverse effects. Regularly

snorting cocaine, for example,

can lead to loss of sense of smell,

nosebleeds, problems with swallowing, hoarseness, and an overall

irritation of the nasal septum,

which can lead to a chronically

inflamed, runny nose. Ingested

cocaine can cause severe bowel

gangrene, due to reduced blood

flow. And, persons who inject

cocaine have puncture marks and

“tracks,” most commonly in their

forearms. Intravenous cocaine

users may also experience an

allergic reaction, either to the

drug, or to some additive in

street cocaine, which can result,

in severe cases, in death. Because

cocaine has a tendency to

decrease food intake, many

chronic cocaine users lose their

appetites and can experience significant weight loss and malnourishment.

Research has revealed a

potentially dangerous interaction

between cocaine and alcohol.

Taken in combination, the two

drugs are converted by the body

to cocaethylene. Cocaethylene

has a longer duration of action in

the brain and is more toxic than

either drug alone. While more

research needs to be done, it is

noteworthy that the mixture of

cocaine and alcohol is the most

common two-drug combination

that results in drug-related death.

NIDA RESEARCH REPORT SERIES 5

Long-term effects 

of cocaine

Addiction

Irritability and 

mood disturbances

Restlessness

Paranoia

Auditory hallucinations

Medical consequences 

of cocaine abuse

Cardiovascular effects

– disturbances in 

heart rhythm

– heart attacks

Respiratory effects

– chest pain

– respiratory failure

Neurological effects

– strokes

– seizures and 

headaches

Gastrointestinal 

complications

– abdominal pain

– nausea
Are 

cocaine abusers 

at risk for 

contracting

HIV/AIDS and

hepatitis B and C?

Y

es. Cocaine abusers, especially those who inject, are

at increased risk for contracting such infectious diseases

as human immunodeficiency

virus (HIV/AIDS) and hepatitis.

In fact, use and abuse of illicit

drugs, including crack cocaine,

have become the leading risk factors for new cases of HIV. Drug

abuse-related spread of HIV can

result from direct transmission of

the virus through the sharing of

contaminated needles and paraphernalia between injecting drug

users. It can also result from indirect transmission, such as an

HIV-infected mother transmitting the virus perinatally to her

child. This is particularly alarming, given that more than 60 percent of new AIDS cases are

women. Research has also shown

that drug use can interfere with

judgement about risk-taking

behavior, and can potentially lead

to reduced precautions about

having sex, the sharing of needles

and injection paraphernalia, and

the trading of sex for drugs, by

both men and women.

Additionally, hepatitis C is

spreading rapidly among injection

drug users; current estimates

indicate infection rates of 65 to

90 percent in this population. At

present, there is no vaccine for

the hepatitis C virus, and the

only treatment is expensive, often

unsuccessful, and may have serious side effects.

What is the 

effect of maternal

cocaine use?

T

he full extent of the effects

of prenatal drug exposure on

a child is not completely

known, but many scientific studies have documented that babies

born to mothers who abuse

cocaine during pregnancy are

often prematurely delivered, have

low birth weights and smaller

head circumferences, and are

often shorter in length. 

Estimating the full extent of

the consequences of maternal

drug abuse is difficult, and determining the specific hazard of a

particular drug to the unborn

child is even more problematic,

given that, typically, more than

one substance is abused. Such

factors as the amount and number of all drugs abused; inadequate prenatal care; abuse and

neglect of the children, due to the

mother’s lifestyle; socio-economic status; poor maternal nutrition;

other health problems; and exposure to sexually transmitted diseases, are just some examples of

the difficulty in determining the

direct impact of perinatal cocaine

use, for example, on maternal and

fetal outcome. 

Many may recall that “crack

babies,” or babies born to mothers who used cocaine while pregnant, were written off by many a

decade ago as a lost generation.

They were predicted to suffer

from severe, irreversible damage,

including reduced intelligence

and social skills. It was later

found that this was a gross exaggeration. Most crack-exposed

babies appear to recover quite

well. However, the fact that most

of these children appear normal

should not be over-interpreted as

a positive sign. Using sophisticated technologies, scientists are

now finding that exposure to

cocaine during fetal development

may lead to subtle, but significant, deficits later, especially with

behaviors that are crucial to success in the classroom, such as

blocking out distractions and

concentrating for long periods of

time.

What treatments

are effective for

cocaine abusers?

T

here has been an enormous

increase in the number of

people seeking treatment for

cocaine addiction during the

1980s and 1990s. Treatment

providers in most areas of the

country, except in the West and

Southwest, report that cocaine is

the most commonly cited drug of

abuse among their clients. The

majority of individuals seeking

treatment smoke crack, and are

likely to be poly-drug users, or

users of more than one substance. The widespread abuse of

cocaine has stimulated extensive

efforts to develop treatment programs for this type of drug abuse.

Cocaine abuse and addiction is a

complex problem involving biological changes in the brain as

well as a myriad of social, familial, and environmental factors.

6 NIDA RESEARCH REPORT SERIES
Therefore, treatment of cocaine

addiction is complex, and must

address a variety of problems.

Like any good treatment plan,

cocaine treatment strategies need

to assess the psychobiological,

social, and pharmacological

aspects of the patient’s drug

abuse.

Pharmacological Approaches

There are no medications currently available to treat cocaine

addiction

specifically.

Consequently,

NIDA is

aggressively

pursuing the

identification

and testing of

new cocaine treatment medications. Several newly emerging

compounds are being investigated

to assess their safety and efficacy

in treating cocaine addiction. For

example, one of the most promising anti-cocaine drug medications

to date, selegeline, is being taken

into multi-site phase III clinical

trials in 1999. These trials will

evaluate two innovative routes of

selegeline administration: a transdermal patch and

a time-released

pill, to determine

which is most

beneficial.

Disulfiram, a

medication that

has been used

to treat alcoholism, has

also been

shown, in clinical studies, to be

effective in reducing cocaine

abuse. Because of mood

changes experienced during the

early stages of cocaine abstinence, antidepressant drugs

have been shown to be of

some benefit. In addition to the

problems of treating addiction,

cocaine overdose results in many

deaths every year, and medical

treatments are being developed to

deal with the acute emergencies

resulting from excessive cocaine

abuse.

Behavioral Interventions

Many behavioral treatments

have been found to be effective

for cocaine addiction, including

both residential and outpatient

approaches. Indeed, behavioral

therapies are often the only available, effective treatment

approaches to many drug problems, including cocaine addiction,

for which there is, as yet, no

viable medication. However, integration of both types of treatments is ultimately the most

effective approach for treating

addiction. It is important to

match the best treatment regimen

to the needs of the patient. This

may include adding to or removing from an individual’s treatment regimen a number of different components or elements. For

example, if an individual is prone

to relapses, a relapse component

should be added to the program.

A behavioral therapy component

that is showing positive results in

many cocaine-addicted populations, is contingency management. Contingency management

uses a voucher-based system to

give positive rewards for staying

in treatment and remaining

cocaine free. Based on drug-free

urine tests, the patients earn

points, which can be exchanged

for items that encourage healthy

living, such as joining a gym, or

going to a movie and dinner.

NIDA RESEARCH REPORT SERIES 7
8NIDA RESEARCH REPORT SERIES

Cognitive-behavioral therapy is

another approach. Cognitivebehavioral coping skills treatment, for example, is a shortterm, focused approach to helping cocaine-addicted individuals

become abstinent from cocaine

and other substances. The underlying assumption is that learning

processes play an important role

in the development and continuation of cocaine abuse and dependence. The same learning processes can be employed to help individuals reduce drug use. This

approach attempts to help

patients to recognize, avoid, and

cope; i.e., recognize the situations

in which they are most likely to

use cocaine, avoid these situations

when appropriate, and cope more

effectively with a range of problems and problematic behaviors

associated with drug abuse. This

therapy is also noteworthy

because of its compatibility with a

range of other treatments patients

may receive, such as pharmacotherapy.

Therapeutic communities, or

residential programs with planned

lengths of stay of 6 to 12 months,

offer another alternative to those

in need of treatment for cocaine

addiction. Therapeutic communities are often comprehensive, in

that they focus on the resocialization of the individual to society,

and can include on-site vocational

rehabilitation and other supportive services. Therapeutic communities typically are used to treat

patients with more severe problems, such as co-occurring mental

health problems and criminal

involvement.

Where can I get

further scientific

information about

cocaine abuse and

addiction?

T

o learn more about cocaine

and other drugs of abuse,

contact the National

Clearinghouse for Alcohol and

Drug Information (NCADI) at

1-800-729-6686. Information specialists are available to assist you

in locating needed information

and resources. 

Fact sheets on the health

effects of drug abuse and other

topics can be ordered free of

charge, in English and Spanish, by

calling NIDA INFOFAX at 1-

888-NIH-NIDA (1-888-644-

6432), or for hearing impaired

persons, 1-888-TTY-NIDA (1-

888-889-6432). 

Information can also be

accessed through the NIDA

World Wide Web site

(http://www.nida.nih.gov) or the

NCADI Web site

(http://www.health.org).

Glossary

Addiction: A chronic, relapsing disease

characterized by compulsive drug-seeking and use and by neurochemical and

molecular changes in the brain.

Anesthetic: An agent that causes insensitivity to pain.

Antidepressants: A group of drugs used

in treating depressive disorders.

Cocaethylene: Potent stimulant created

when cocaine and alcohol are used

together.

Coca: The plant, Erythroxylon, from

which cocaine is derived. Also refers to

the leaves of this plant.

Crack: Short term for a smokable form

of cocaine. 

Craving: A powerful, often uncontrollable desire for drugs.

Dopamine: A neurotransmitter present in

regions of the brain that regulate movement, emotion, motivation, and the feeling of pleasure.

Neuron: A nerve cell in the brain.

Physical dependence: An adaptive physiological state that occurs with regular

drug use and results in a withdrawal syndrome when drug use is stopped; usually

occurs with tolerance.

Poly-drug user: An individual who uses

more than one drug.

Rush: A surge of pleasure that rapidly

follows administration of some drugs.

Tolerance: A condition in which higher

doses of a drug are required to produce

the same effect as during initial use;

often is associated with physical dependence.

Vertigo: The sensation of dizziness.

Withdrawal: A variety of symptoms that

occur after use of an addictive drug is

reduced or stopped.

References

Gold, Mark S. Cocaine (and Crack): Clinical Aspects (181-

198), Substance Abuse: A Comprehensive Textbook, Third 

Edition, Lowinson, ed. Baltimore, MD: Williams & 

Wilkins, 1997.

Harvey, John A. and Kosofsky, Barry, eds. Cocaine: Effects 

on the Developing Brain. Annals of the New York 

Academy of Sciences, Volume 846, 1998.

National Institute on Drug Abuse. Epidemiologic Trends in 

Drug Abuse: Vol. 1. Highlights and Executive Summary of

the Community Epidemiology Work Group. NIH Pub. No. 

98-4207. Washington, DC: Supt. of Docs., U.S. Govt. 

Print. Off., 1997.

National Institute on Drug Abuse. NIDA Infofax, Crack and 

Cocaine, 1998.

National Institute on Drug Abuse. National Survey Results on

Drug Use From the Monitoring the Future Survey, 1998.

Office of National Drug Control Policy. The National Drug 

Control Strategy, 1998: A Ten Year Plan.

Snyder, Solomon H. Drugs and the Brain (122-130). New 

York: Scientific American Library, 1996. 

Substance Abuse and Mental Health Services Administration.

Preliminary Results from the 1997 National Household 

Survey on Drug Abuse. SAMHSA, 1998.

NIH Publication Number 99-4342. Printed May 1999. Feel free to reprint this publication.