changes in the function of the IMMUNE SYSTEMthat
may make users more susceptible to INFECTION.
See also CLUB DRUGS; CORONARY ARTERY DISEASE
(CAD); DRUG INTERACTION; SUBSTANCE ABUSE PREVEN-
TION.
amphetamines Drugs that stimulate the CENTRAL
NERVOUS SYSTEM. Amphetamines belong to the
phenylethylamine class of drugs, a large DRUGfam-
ily that also includes amphetamine-like drugs with
similar actions and effects. Amphetamines and
amphetamine-like drugs are SCHEDULED DRUGSin
the United States, requiring a physician’s prescrip-
tion for legal use and possession. Those that are
schedule 2 drugs further must meet narrowly
defined treatment criteria. Methcathinone and
cathinone, though ingredients of schedule 2 and
schedule 3 drugs, are schedule 1 drugs in their
pure forms and do not have therapeutic uses.
Amphetamines and amphetamine-like drugs
have dual activity in the BRAIN: They increase the
release of serotonin, DOPAMINE, and NOREPINEPHRINE;
and they block the reuptake of dopamine, norepi-
nephrine, and monoamine oxidase (MAO). These
neurotransmitters have numerous roles in brain
activities in regard to mental focus, concentration,
and mood. Consequently amphetamines and
amphetamine-like drugs increase alertness, reduce
APPETITE, and establish a sense of confidence and
well-being. Therapeutic uses include treatment for
NARCOLEPSY, ATTENTION DEFICIT HYPERACTIVITY DISOR-
DER (ADHD), weight loss in morbid OBESITY, and
alertness in military pilots.
Abuse of amphetamines and amphetamine-like
drugs occurs to take advantage of the euphoria,
heightened alertness, and diminished need for
sleep. As well, the stimulant effects of these drugs
may intensify LIBIDO(sex drive), though ERECTILE
DYSFUNCTIONis a common SIDE EFFECTof chronic
abuse. TOLERANCEdevelops quickly, escalating the
amount of drug necessary to produce the desired
effects. Because dopamine is also essential for
movement, its presence in excess results in invol-
untary movements (DYSKINESIA). Short-term side
effects that usually go away when the drug leaves
the body include trembling, HALLUCINATION,
increased perspiration, and HEADACHE. Side effects
with long-term use that may be long lasting or
permanent include SCHIZOPHRENIA-like PSYCHOSIS,
PARANOIA, SLEEP DISORDERS, DEPRESSION, ARRHYTHMIA,
and aggressive behavior. Amphetamines and
amphetamine-like drugs have high risk for psy-
chologic DEPENDENCEand ADDICTION with chronic
abuse.COMMON AMPHETAMINES
AND AMPHETAMINE-LIKE DRUGS
amphetamine benzphetamine
cathinone dextroamphetamine
diethylpropion mazindol
METHAMPHETAMIN Emethcathinone
methylphenidate phendimetrazine
phentermineSee also BARBITURATES; CAFFEINE; HYPNOTICS; NAR-
COTICS; NICOTINE; OPIATES; PERFORMANCE-ENHANCING
SUBSTANCES; SUBSTANCE ABUSE TREATMENT.anabolic steroids and steroid precursors Hor-
mones or hormonelike substances taken to
increase MUSCLE mass and STRENGTH. Anabolic
steroids are class 3 SCHEDULED DRUGSin the United
States, legally available only with a physician’s
prescription. As substances of abuse, anabolic
steroids and steroid precursors (substances the
body metabolizes into anabolic steroids) are popu-
lar among athletes, bodybuilders, people who
work in jobs that require physical strength, and
people who desire a particular physique. Anabolic
steroids are available in injectable forms and oral
tablets.Therapeutic Uses
Therapeutic uses for anabolic steroids are very
limited; many anabolic steroid products are illicit.
Though most anabolic steroids are androgenic
(increase the production of ANDROGENS, the male
sex hormones), anabolic steroids that are nonan-
drogenic (increase muscle mass without intensify-
ing masculine traits) became available in the late
1990s for therapeutic uses. Anabolic nonandro-
genic steroids appear to have fewer undesirable
side effects, though the full extent of any long-
term consequences remains unknown.
Most commonly doctors prescribe a TESTOS-
TERONEproduct for androgen supplementation or
therapy and a nonandrogenic anabolic steroid
to treat growth-related disorders in children.anabolic steroids and steroid precursors 321