Introduction:
Methylphenidate (d,l-threo-methyl-I-phenyl-2-piperidine-acetate
hydrochloride) is a central nervous system (CNS) stimulant that
has been marketed in the United States since the 1950s.
For many years, Ritalin ® (immediate release (IR) product), was
the only brand-name product available. In recent years,
other IR, extended release (ER), and long acting (LA)
methylphenidate products have entered the market. These
products are primarily prescribed to children for the treatment
of attention deficit hyperactivity disorder (ADHD).
Domestic and worldwide use of methylphenidate has increased
dramatically since 1990. According to the 2004 United
Nations International Narcotic Control Board (INCB) report, the
United States is the main consumer of methylphenidate accounting
for about 70 percent of the global medical use of
methylphenidate.
Licit Use:
Methylphenidate is used almost exclusively for the treatment of
ADHD. There is a considerable body of literature on the
short-term efficacy of methylphenidate pharmaco-therapy for the
treatment of ADHD. However, attentional improvement is not
diagnostic of ADHD. There is no diagnostic test that can
confirm an ADHD diagnosis.
Recent data suggests that some children may continue to have
significant ADHD-symptoms into adulthood. As a
consequence, the prescription of methylphenidate for individuals
18 and older is the most rapidly growing market. Longer
acting products, primarily Concerta®, have gained a significant
share of the total methylphenidate market. The IMS Health
National Prescription Audit Plus™ reported 14.8
million methylphenidate prescriptions dispensed in 2008.
Chemistry/Pharmacology:
Methylphenidate is a CNS stimulant and produces a number of
effects including appetite suppression, increased alertness and
increases in blood pressure, heart rate, respiration, and body
temperature. Almost complete absorption of IR
methylphenidate occurs after oral administration with peak
plasma levels in about 2 hours. It is extensively
metabolized and about 80% of the dose is excreted in the urine
as ritalinic acid. Only 20% of the administered oral dose
is bioavailable due to extensive first-pass metabolism.
Biochemically, methylphenidate enhances the release and
blocks the reuptake of dopamine (DA) and norepinephrine (NE) in
mammalian brain. Pharmacologically methylphenidate is most
closely related to cocaine. In human subjects,
methylphenidate binds to the same receptor sites as cocaine in
the brain and produces effects that are indistinguishable from
cocaine.
Illicit Use:
Like other potent stimulants, methylphenidate is abused for its
“feel good” stimulant effects. The occasional abuser
may use methylphenidate as a study aid to increase attention and
stay awake. Others may use methylphenidate recreationally
and combine it with alcohol or some other depressant to feel
more alert or less drunk. Serious methylphenidate abusers
often snort or inject methylphenidate for its intense euphoric
effects or to alleviate the severe depression and craving
associated with a stimulant withdrawal syndrome.
Monitoring the Future (MTF) is a National Institute on Drug
Abuse (NIDA) funded study conducted by the University of
Michigan. In 2008, the MTF survey indicated that 3.4% of
12th grade students, 2.9% of 10th grade students and 1.6% of 8th
grade students reported nonmedical use of Ritalin in the past
year.
The National Survey on Drug Use and Health (NSDUH)
is a database that measures drug use by people living
in households. In 2007, the highest non-medical use of
methylphenidate among youth was in the 18-25 year old age group
with 4.8% reporting lifetime non-medical use. It is
estimated that 1.61 million people misused methylphenidate in
their lifetime, according to the 2007 NSDUH report.
The American Association of Poison Control Centers (AAPCC)
report indicates 8,766 methylphenidate case mentions and 6,062
single exposures in 2006. In 2007, 8,994 case mentions and
6,355 single exposures reported to AAPCC were associated with
methylphenidate. Nonmedical use of methylphenidate accounted for
2,192 visits to the emergency department in 2006 according to
the Drug Abuse Warning Network (New DAWN ED).
The National Forensic Laboratory Information System (NFLIS)
is a database that collects data on analyzed drug seizures from
federal, state and local forensic laboratories. In 2008,
the NFLIS reported law enforcement submitted 1,382 exhibits of
methylphenidate to state and local labs and 81 exhibits to
federal labs to be analyzed.
User Population:
While a wide spectrum of the population has abused
methylphenidate products, the primary abusers are individuals
less than 25 years of age; who often obtain methylphenidate from
a friend or classmate and use this drug as a study aid or to
party.
Illicit Distribution:
Unlike other potent stimulants, there is no clandestine
production of methylphenidate and diverted pharmaceutical
products are the only source for abuse purposes.
Methylphenidate is obtained from fraudulent prescriptions,
doctor shopping, pharmacy theft and from friends or associates
who have obtained the drug through a prescription.
Control Status:
Methylphenidate is a Schedule II substance under the Controlled
Substances Act.
Comments and additional information are welcomed by the
Office of Diversion Control, Drug and Chemical Evaluation
Section. Fax 202-353-1263, telephone 202-307-7183, or Email ODE@usdoj.gov.