Drugs and Chemicals of
Concern > Methylphenidate
METHYLPHENIDATE
(Trade Names: Ritalin- (IR, LA, and SR),
Concerta, Metadate- (CD and ER),
Methylin- (IR and ER) and Focalin- (IR and ER))
June 2006
DEA/OD/ODE
Introduction:
Methylphenidate (d,l-threo-methyl-I
-phenyl-2-piperidine-acetate hydrochloride) is a central nervous system
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.
Chemistry/Pharmacology:
Methylphenidate is a CNS stimulant and
produces a number of effects including, dose related increases in blood
pressure, heart rate, respiration, body temperature, appetite suppression, and
attention. 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
cites 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 2004, 4.4% of 12th grade students, 3.4%
of 10th grade students and 2.4% of 8th grade students
reported nonmedical use of methylphenidate in the previous year.
The National Survey on Drug Use and
Health (NSDUH, formerly the National Household Survey on Drug Abuse)
is a database that measures drug use by people living in households. The
highest non-medical use of methylphenidate was reported among 18-25 years of
age with 5.4% reporting lifetime non-medical use.
According to poison control data, Toxic
Exposure Surveillance System (TESS), exposures for methylphenidate are
numerous and have resulted in serious medical outcomes and deaths. In 2004
there were over 8,000 methylphenidate exposures reported to TESS and about 12%
of these exposures resulted in serious medical outcomes.
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.
Comments and additional information are
welcomed by the Drug and Chemical Evaluation Section, FAX
202-353-1263 or telephone 202-307-7183.
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