is an addictive stimulant drug that strongly activates certain systems in the
brain. Methamphetamine is closely related chemically to amphetamine, but the
central nervous system effects of methamphetamine are greater. Both drugs have
some medical uses, primarily in the treatment of obesity, but their therapeutic
use is limited.
is made in illegal laboratories and has a high potential for abuse and
dependence. Street methamphetamine is referred to by many names, such as
"speed," "meth," and "chalk." Methamphetamine
hydrochloride, clear chunky crystals resembling ice, which can be inhaled by
smoking, is referred to as "ice," "crystal," and
releases high levels of the neurotransmitter dopamine, which stimulates brain
cells, enhancing mood and body movement. It also appears to have a neurotoxic
effect, damaging brain cells that contain dopamine and serotonin, another
neurotransmitter. Over time, methamphetamine appears to cause reduced levels of
dopamine, which can result in symptoms like those of Parkinson's disease, a
severe movement disorder.
is taken orally or intranasally (snorting the powder), by intravenous injection,
and by smoking. Immediately after smoking or intravenous injection, the
methamphetamine user experiences an intense sensation, called a "rush"
or "flash," that lasts only a few minutes and is described as
extremely pleasurable. Oral or intranasal use produces euphoria - a high, but
not a rush. Users may become addicted quickly, and use it with increasing
frequency and in increasing doses.
research going back more than 20 years shows that high doses of methamphetamine
damage neuron cell-endings. Dopamine- and serotonin-containing neurons do not
die after methamphetamine use, but their nerve endings ("terminals")
are cut back and re-growth appears to be limited.
central nervous system (CNS) actions that result from taking even small amounts
of methamphetamine include increased wakefulness, increased physical activity,
decreased appetite, increased respiration, hyperthermia, and euphoria. Other CNS
effects include irritability, insomnia, confusion, tremors, convulsions,
anxiety, paranoia, and aggressiveness. Hyperthermia and convulsions can result
causes increased heart rate and blood pressure and can cause irreversible damage
to blood vessels in the brain, producing strokes. Other effects of
methamphetamine include respiratory problems, irregular heartbeat, and extreme
anorexia. Its use can result in cardiovascular collapse and death.
A study in
Seattle confirmed that methamphetamine use was widespread among the city's
homosexual and bisexual populations. Of these groups, members using
methamphetamine reported they practice sexual and needle-use behaviors that
place them at risk of contracting and transmitting HIV and AIDS.