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DRUGS |
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Testimony before the U.S. House of Representatives
Statement of Nora D. Volkow Director, National
Institute on Drug Abuse, National Institute of Health
Committee on House Government Reform Subcommittee on Criminal Justice,
Drug Policy, and Human Resources
July 26, 2006
Mr. Chairman and Members of the Subcommittee:
Thank you for inviting the National Institute on Drug Abuse (NIDA),
a component of the National Institutes of Health (NIH), an agency
of the U.S. Department of Health and Human Services, to participate
in this important hearing. Prescription drugs are powerful allies
in our quest to alleviate human suffering. And psychotherapeutics-those
drugs that target the central nervous system (CNS)-are responsible
for remarkable advances in our ability to understand and reduce the
burden of mental illness and physical pain. However, as is often the
case with beneficial technologies, there is a negative side, too.
Because some of the psychotherapeutic drugs act, either directly or
indirectly, upon the same brain systems affected by addictive drugs,
their non- medical use carries a substantial abuse liability that
NIDA's efforts are designed to assess, reduce, and make publicly known.
I am pleased to have the opportunity today to share with you what
we know and where we are relative to the issue of prescription drug
abuse in this country.
What is the Scope of Prescription Drug Abuse in this Country?
Several indicators show that prescription drug abuse is a significant
problem in the United States and one that has been increasing recently.
* Approximately 6 million persons 12 and older used psychotherapeutic
drugs for non-medical purposes in 2004, which represents 2.5 percent
of the U.S. population. Most of them reported abusing opiate pain
relievers in particular, with young adults (18-25) showing the greatest
increases in lifetime use between 2002 and 2004 (National Survey on
Drug Use and Health (NSDUH), conducted by HHS's Substance Abuse and
Mental Health Services Administration).
* In 2004, 2.4 million persons ages 12 or older initiated non- medical
use of prescription pain relievers during the past year, surpassing
for the first time in the life of the survey, those who initiated
abuse of marijuana (2.1 million) (National Survey on Drug Use and
Health).
* Among 12th graders, in 2005, 9.5% reported past-year non- medical
use of Vicodin, and 5.5% reported past-year non-medical use of OxyContin.
Data show an increase in the abuse of OxyContin between 2002 and 2005
among 12th graders (NIDA's 2005 Monitoring the Future survey [MTF]).
Percent of 12th Graders Reporting Nonmedical Use of Oxycontin and
Vicodin in the Past Year Remained High
* Past-year non-medical use of stimulant medications is also high,
with 8.6% of 12th graders reporting abuse of amphetamine (a parent
class of drugs that includes methamphetamine), and 4.4% reporting
abuse of methylphenidate (Ritalin) (2005 MTF).
Prescription Drugs with Abuse Liability The psychotropic prescription
drugs that present abuse liability fall into three broad categories:
(1) stimulants, which are prescribed to treat attention-deficit hyperactivity
disorder (ADHD) and narcolepsy and include drugs such as Ritalin and
Adderall; (2) opioids, which are mostly prescribed to treat moderate
to severe pain and include drugs such as OxyContin and Vicodin; and
(3) CNS depressants, typically prescribed for the treatment of anxiety,
panic, sleep disorders, acute stress reactions, and muscle spasms
and include drugs such as Valium, Librium, and Xanax.
To understand how these drugs can have both beneficial effects in
patients and serious abuse and health liabilities in people taking
them for non-medical reasons requires knowledge of how drugs exert
their effects in the brain. As noted above, there can be substantial
overlap between the brain systems that mediate the therapeutic effects
of psychotropic medications and those responsible for the reinforcing
effects of drugs of abuse. However, while the molecular targets in
the brain for some medications may be the same ones as those for some
of the drugs of abuse, differences in how much of the drug gets into
the brain and how fast it gets there determine whether desirable (therapeutic)
or undesirable (abuse and addiction) effects will follow. Factors
such as drug dosage, route of administration (which regulates the
speed of drug delivery to the brain), and user expectations are crucial.
For example, the stimulant methylphenidate (Ritalin) has much in common
with cocaine-they bind to similar sites in the brain and they both
increase the brain chemical dopamine through the same molecular targets.
And when both drugs are administered intravenously, they cause a rapid
and large increase in dopamine, which a person experiences as a rush
or high. However, when methylphenidate is taken orally, as prescribed,
it elicits a gradual and sustained increase in dopamine, which is
not perceived as euphoria and instead produces the expected therapeutic
effects seen in many patients.
Stimulants (Ritalin, Adderall) Act Like Cocaine Directly in the Dopamine
Cells
Scientists and physicians are learning how to exploit such differences
to develop formulations and dosage regimens for optimal therapeutic
value and minimal abuse and addiction potential. Unfortunately, these
strategies can sometimes be undermined by sophisticated abusers. Consider
OxyContin, a pain medication originally marketed as having a low potential
for abuse because it was formulated to ensure a slow and gradual release
of the drug. Abusers quickly learned that the pills could be crushed
and their contents injected or snorted, releasing the entire dosage
at once. What abusers do not realize is the great risk of overdose
and other devastating consequences that may result from this practice.
Now widespread in its abuse, OxyContin is the only commonly prescribed
opioid analgesic that comes with a "black box" warning.
Why is this happening now?
The recent increase in the extent of prescription drug abuse in this
country is likely the result of a confluence of factors, such as:
significant increases in the number of prescriptions;1 significant
increases in drug availability;2 aggressive marketing by the pharmaceutical
industry;3 the proliferation of illegal Internet pharmacies that dispense
these medications without proper prescriptions and surveillance;4
and a greater social acceptability for medicating a growing number
of conditions. The fact that doctors are prescribing these drugs legitimately
and with increasing frequency to treat a variety of ailments leads
to the misguided and dangerous conclusion that their non-medical use
should be equally safe. This misperception of safety may contribute,
for example, to the casual attitude of many college students towards
abusing stimulants to improve cognitive function and academic performance.
Notably, between 1987 and 1996, a nearly four-fold increase occurred
in the prevalence of stimulant prescriptions among youth; this increase
has persisted, but has since remained near the 1996 levels. Similarly,
the number of oxycodone and hydrocodone prescriptions has more than
doubled between 1994 and 2001. While such increases in psychoactive
drug prescriptions reflect improved diagnostic practices and treatment
options, it would be naive not to also consider the contribution of
market forces in the emergence of these trends. For example, sales
of ADHD medications in the United States reached $3.1 billion in 2004.
But even at this robust level of sales, the number of prescriptions
for ADHD medications is less than 20 percent when compared to the
120 million prescriptions written in 2005 for pain medications containing
hydrocodone or oxycodone. Such high exposure rates suggest that we
need to discover the potential abuse consequences for youth and other
populations at risk for addiction.
Special populations, specific risks and consequences
Indeed, the growing problem of prescription drug abuse in this country,
which affects individuals at all stages in life, is alarming. In adolescents,
the increase in prescription drug abuse reported over the past 5 years
contrasts with the steady declines in overall illicit drug abuse that
has been reported in this group over this same time period. These
trends in adolescent are particularly problematic because adolescence
is the period of greatest risk not only for drug experimentation but
also for developing addiction. Also at this stage the brain is still
developing and exposure to drugs could interfere with these developmental
changes.
Today we know that the last part of the brain to fully mature is the
prefrontal cortex, a region that governs judgment and decision-making
functions. This may help explain why teens are prone to risk-taking
and why high rates of risky behaviors, including abuse of alcohol
and other drugs, have been reported among those who abuse prescription
drugs. The 2001 NSDUH survey reveals that youth who had used prescription
drugs non-medically in the past year were almost four times more likely
to have also used other illicit drugs.
We are also particularly concerned about older Americans, who currently
make up only 13 percent of the population but who receive approximately
one-third of all medications prescribed in the Nation. For practical
reasons, older patients are sometimes prescribed long-term and multiple
prescriptions, which could lead to abuse or unintentional misuse.
These medications can interact with over-the-counter medicines and
dietary supplements, which older adults tend to consume in significant
quantities. Older adults also experience higher rates of other illnesses,
normal changes in drug metabolism, and increased susceptibility to
toxic effects. It is hardly surprising then that abuse or unintentional
misuse of prescription drugs by elderly persons could lead to more
severe health consequences. For example, elderly persons who take
benzodiazepines such as Valium, Librium, and Xanax are at increased
risk for cognitive impairment, leading to possible falls as well as
vehicular accidents. Moreover, not all physicians know that prescribing
benzodiazepines to elderly people is contraindicated for these reasons.
Therefore, physician education is a necessary part of any effort to
curb the abuse of prescription medications.
Prescription drug abuse must also be carefully tracked among women
because of their combined vulnerabilities. First, women are more likely
than men to suffer from depression, anxiety, trauma, and victimization,
all of which frequently appear with substance abuse in the form of
comorbidities. Second, girls and women report using drugs to cope
with stressful situations in their lives. Third, studies suggest that
women are significantly more likely than men to be prescribed an abusable
drug, particularly in the form of narcotics and anti-anxiety medications.
These cumulative risks notwithstanding, adult men and women have roughly
similar rates of non-medical use of prescription drugs; 12-17-year-old
girls, however, are more likely than boys to abuse psychotherapeutic
drugs, including stimulants.
In addition to the risk to women is the potential for harm to the
developing fetus. Therefore, more research is needed on the extent
and patterns of prescription drug abuse during pregnancy. National
projections from survey data collected between 2002 and 2004 suggest
that 109,000 pregnant women abused pain relievers in the past year.
And past-year abuse of any stimulants (including methamphetamine)
or sedatives/tranquilizers was reported by 32,000 and 56,000 pregnant
women, respectively. However, there is overall less non-medical abuse
of prescription psychotherapeutics among pregnant than among non-pregnant
women (6% and 9.3%, respectively), although this is not the case in
pregnant adolescent girls (15-17 years), in whom the rate of prescription
drug abuse is higher than in those who are not pregnant.
What Abuse of Prescription Drugs Does to the Brain and Body
When taken under the supervision of a physician, prescription drugs
can be lifesaving, but when abused, they can be as life- threatening
as illicit drugs. Stimulants can elevate blood pressure, increase
heart rate and respiration, cause sleep deprivation, and elicit paranoia.
Their continued abuse, or even one high dose, can cause irregular
heartbeat, heart failure, and seizures. Painkillers and anti-anxiety
medications can cause depressed respiration and even death, and CNS
depressants can also induce seizures when a reduction in their chronic
use triggers a sudden rebound in brain activity. Particularly dangerous
is when young people indiscriminately mix and share prescription drugs,
also combining them with alcohol or other drugs. In an environment
where opiate analgesics are the most frequently prescribed medication,
with over 100 million prescriptions written every year, this risky
practice is likely to contribute to the growing trend of drug abuse-related
emergency room visits involving prescribed narcotics. And again, these
classes of psychotherapeutic drugs have a real potential for leading
to addiction, especially if abused repeatedly, at high doses, and/or
by susceptible individuals.
As Prescriptions Have Increased Emergency Room Visits For Non- Medical
Abuse Have Also Increased
What is NIDA doing about it?
Recent research has revealed an increasing problem with prescription
drug abuse, yet we still must get a better picture of the broader
epidemiologic patterns of abuse. We need to learn more about how specific
drugs are abused and in what quantities and combinations, why they
are abused and how often, as well as other associated medical and
health consequences. We also need a better understanding of the regional
and local variations in patterns of abuse, and the influence of age,
gender, and race/ethnicity-all of which can provide an essential foundation
for developing effective and targeted interventions and services.
Epidemiology and surveillance
We have at our disposal a series of surveillance instruments, which
we use to continuously monitor trends in all forms of drug abuse,
including the abuse of prescribed medications. For example, 21 Community
Epidemiology Work Group (CEWG) sentinel sites across the Nation provide
ongoing community-level surveillance of drug abuse profiles through
analysis of quantitative and qualitative research data. At its 56th
semiannual meeting, CEWG representatives held a special conference
on patterns and trends in the abuse of prescription drugs, information
later disseminated to drug abuse prevention and treatment agencies,
public health officials, researchers, and policymakers. The application
of this and other tools have allowed NIDA to stay ahead of the curve
and to identify potentially troublesome trends as soon as they begin
to surface in the population, such as those that have prompted NIDA-
supported researchers to investigate the patterns and sources of illicit
use of prescription medications in high school and college students.
Research initiatives
In response to the mounting evidence of increased abuse of prescribed
medications, NIDA has orchestrated a multi-pronged strategy intended
to complement and expand our already robust portfolio of basic, preclinical,
and clinical research aimed at better understanding the prescription
drug phenomenon. An important item on this agenda is our latest initiative
on "Prescription Opioid Use and Abuse in the Treatment of Pain," which
encourages a multidisciplinary approach using both human and animal
studies from across the sciences to examine factors (including pain
itself) that predispose or protect against opioid abuse and addiction.
Particularly important is to assess how genetic influences affect
the vulnerability of an individual exposed to pain medication to become
addicted. This type of information will help develop screening and
diagnostic tools that primary care physicians can use to assess the
potential for prescription drug abuse in their patients. Because opioid
medications are prescribed for all age groups, NIDA is also encouraging
research that assesses the effects of their chronic use over the entire
lifespan.
Another important initiative pertains to the development of new pain
medications or formulations with minimum abuse potential. We have
witnessed some remarkable advances in this area of research recently
with the introduction of buprenorphine/naloxone, a combined formulation
for the treatment of opiate addiction with dramatically reduced abuse
liability. Compounds that act on a combination of two distinct opioid
receptors (mu and delta), have been shown in preclinical studies to
induced strong analgesia without producing tolerance or dependence.
Researchers are also getting closer to developing a new generation
of non-opioid-based medications for severe pain that would circumvent
the brain reward pathways, greatly reducing abuse potential. Included
are compounds that work through a cannabinoid receptor subtype located
primarily in the peripheral nervous system.
Treatment and Prevention
Treatment and prevention of drug abuse and addiction are key NIDA
goals. Our efforts to identify effective treatments for prescription
opioid abuse and addiction include conducting a multi-center study
of more than 600 participants, employing our Clinical Trials Network
(CTN) to evaluate treatment regimens using oral buprenorphine/naloxone.
In addition, behavioral therapies, an integral part of all treatment
strategies, continue to be a mainstay for treating stimulant addiction.
Although scientifically validated prevention programs have been shown
to be effective in curbing the prevalence of substance abuse and addiction
in general, non-medical use of prescription drugs in some ways presents
a more difficult scenario than illicit drugs. Because prescription
drugs are safe and effective when used properly and are broadly marketed
to the public, the notion that they are also harmful and addictive
when abused can be a difficult one to convey. Thus, we need focused
research to discover targeted communication strategies that effectively
address this problem. Reaching this goal may be significantly more
complex and nuanced than developing and deploying effective programs
for the prevention of abuse of illicit drugs, but good prevention
messages based on scientific evidence will be hard to ignore and will
make their mark in time.
In the meantime, the centerpiece of our strategy to curtail the prevalence
of prescription drug abuse must center around our efforts to disseminate
accurate information about the serious health consequences involved,
with particular focus on addiction potential. Our messages aim to
reach not only the general public and populations at heightened risk,
such as adolescents, but also physicians and other health care providers,
whose training on proper diagnostic and monitoring practices is vitally
important. We will continue our close collaborations with physicians'
organizations, the Office of National Drug Control Policy (ONDCP),
SAMHSA and other Federal agencies, as well as professional associations
with a strong interest in preserving public health. We regard these
preventive efforts an integral part of NIDA's mission.
Conclusion
In conclusion, we should not be surprised that the availability of
more, new, and better psychotherapeutics has been followed more recently
by an upswing in the prevalence of their non- medical use by varied
populations. However, we should be seriously concerned: prescription
drugs can be powerfully addictive and their abuse accompanied by toxic
and sometimes fatal consequences.
Perhaps one of the most challenging aspects of this trend is that
prescription drug abuse affects individuals of all ages. On the other
hand, we are fortunate to have in place an efficient warning system
that has helped us to spot this problem at a relatively early stage
and to quickly implement activities designed to keep it in check.
Consistent with one of NIDA's most important goals, our response has
been framed by our commitment to translate what we know from research
to help the public better understand drug abuse and addiction, and
to develop more effective strategies for their prevention and treatment.
The emerging nature of the prescription drug abuse problem, combined
with our substantial but still growing knowledge of its underlying
causes and resulting consequences, make us optimistic about our chances
to rationally and successfully address this challenge.
Thank you for allowing me to share this information with you. I will
be happy to answer any questions you may have.
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