Amphetamines
This
page will help you better understand what amphetamines
are, how they work in the nervous system and routes of
administration. This section will provide you with what you need
to know about amphetamines, so that you can understand their role in
psychosis and the dopamine hypothesis of schizophrenia.
Amphetamines
are a class of
synthetic drugs. They were originally used as an appetite
suppressent (weight control), and in treatment of narcolepsy and
attention deficit hyperactivity disorder, commonly known as ADHD.
These drugs were meant to help treat some medical conditions, but they
have since become a commonly abused drug. If not obtained
in a pharmacy by way of prescription, they are usually bought on the
street, leaving them very impure or mixed with other dangerous drugs.
Amphetamines are
exogenous dopamine agonists. Exogenous means
that they are found outside of the body and agonist means that they
stimulate the release of a
neurotransmitter. Exogenous dopamine agonist therefore means that they
are consumed and stimluate the release of the neurotransmitter
dopamine. In the nervous system, amphetamines act on dopamine
receptors. More specifically, amphetamines act on special kinds
of dopamine receptors called D2 receptors. This binding
results in increased dopamine in the synaptic
cleft. An increase of neurotrasmitter in the synaptic cleft
increases the likelihood that the
receptors on the postsynaptic cell will be activated.
Abusers
of the drug
use it to achieve the euphoric feeling that it provides. The
achieved
high from amphetamines includes exhilaration, increases in feelings of
power and strength,
increased energy, self-confidence, focus and an overall euphoria.
People on
amphetamines will often stay awake for long periods of time and will
not eat
normally. Users are typically aggressive and have violent tendencies.
Because
the body has no way to break down amphetamines, their effects can last
much
longer than many other drugs, including cocaine, which has similar
effects. The
long-term effects of amphetamines effects include more than just an
increase in
the likelihood of the stereotypic initial effects. Additionally,
because it is
a stimulant, cardiovascular problems including heart failure can result
from
prolonged use as well as just one single large acute dose.
Amphetamines
may be
snorted, swallowed or injected. The resulting high varies by the route
of
administration. Intravenous injection leads to the quickest high. It
gets into
the blood stream immediately and begins to act on the brain within
seconds.
Snorting allows for delivery to the brain through the mucus membranes
in the
nose and this reaches the brain very rapidly as well. Swallowing
amphetamines
takes longer to achieve their effect. The drug must pass through the
digestive
system before it reaches the blood, which can take 20-30 minutes; this
has. When taken orally, drug abusers say the effects tend to feel
smoother and longer lasting.
Pictures contained in the web page courtesy of
http://www.newscientist.com/blog/shortsharpscience/uploaded_images/pills_medium-784840.jpg
http://homepage.eircom.net/~pcorcoranshc/images/amphetamines.jpg
http://www.minddisorders.com/images/gemd_01_img0012.jpg
http://www.police.qld.gov.au/Resources/Internet/services/images/IMAGE1.jpg
