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Lorema Reyeg
Arianne Nagrampa
Simon Evangelio
Stimulants
Stimulant drugs are drugs that temporarily increase
alertness and awareness. They usually have increased
side-effects with increased effectiveness, and the
more powerful variants are therefore often
prescription medicines or illegal drugs.
Function
Stimulants increase the activity of either the sympathetic
nervous system, the central nervous system or both. Some stimulants
produce a sense of euphoria, in particular the stimulants which exert
influence on the CNS.
Stimulants are used therapeutically to increase or maintain
alertness, to counteract fatigue in situations where sleep is not
practical to counteract abnormal states that diminish alertness
consciousness, such as in narcolepsy, to promote weight loss
(phentermine) as well as to enhance the ability to concentrate in
people diagnosed with attentional disruptions (especially ADHD).
Occasionally, they are also used to treat depression. Stimulants
are sometimes used to boost endurance and productivity as well as to
suppress appetite, therefore also known to promote eating disorders
such as anorexia if abused. The euphoria produced by some stimulants
leads to their recreational use, although this is illegal in the majority of
jurisdictions.
☻Caffeine, found in beverages such as coffee and soft drinks, as well as
nicotine, which is found in tobacco, are among some of the world's most
commonly used stimulants.
☻Examples of other well known stimulants include ephedrine,
amphetamines, cocaine, methylphenidate, MDMA, and modafinil.
Stimulants are commonly referred in slang as "uppers".
☻Stimulants with significant abuse potential are very carefully controlled
substances in America and most other jurisdictions. Some may be legally
available only by prescription (e.g. methamphetamine, brand name
Desoxyn, mixed amphetamine salts, brand name Adderall,
dexamphetamine, brand name Dexedrine) or not at all (e.g.
methcathinone).
Kinds of
Stimulants
Amphetamine
Amphetamines increase the heart and respiration rates, increase
blood pressure and in some users, dilate the pupils of the eyes
and decrease appetite. Like NDRIs, amphetamine increases the
levels of norepinephrine and dopamine in the brain via reuptake
inhibition; however, the more important mechanism by which
amphetamines cause stimulation is through the direct release of
these catecholamines from storage vesicles in cells.
Amphetamines are known to cause elevated mood and euphoria
as well as rebound depression and anxiety. Other possible effects
include blurred vision, insomnia, and dizziness.
Amphetamines are sometimes prescribed therapeutically
by physicians and their availability makes them prime
candidates for misuse . Used properly, amphetamines
increase alertness, concentration and physical
endurance. They are often prescribed to counter the
effects of narcolepsy, a disorder marked by episodes of
uncontrollable sleep, and to help patients with learning
disabilities such as ADD and ADHD. Dextrorotary
methamphetamine is occasionally used in the treatment
of AD(H)D that does not respond sufficiently to
traditional amphetamines. On occasion, major
depression is treated with amphetamines as well.
Amphetamines can be used as an add-on to
antidepressant therapy as well, with some success in
certain populations.
Methylenedioxymethamphetamine
Methylenedioxymethamphetamine (MDMA) is a drug that comes either
in tablet or capsule form (known as ecstasy, zoom, scrap), as a powder or
crystal. Stimulant effects of MDMA include increased blood pressure and
heart rate, loss of appetite, rapid sweating, and a dry mouth and throat.
Ecstasy pills often contain amounts of other drugs which may include any
of a wide range of substances such as MDA, MDEA, MBDB, PCP, DXM,
Ketamine, Caffeine, Amphetamine, Methamphetamine, Ephedrine,
cinnamedryl Pseudoephedrine, Aspirin, Paracetamol, and, in a small
number of cases, PMA, Cocaine, Fentanyl, mCPP, BZP+TFMPP, DOB and
2C-B, In some cases the substance sold as ecstasy may not contain
MDMA at all.
MDMA was historically used in a therapeutic setting by a small number
of psychiatrists for marriage counseling, before it was outlawed by the
DEA because of its widespread recreational use. As of 2001, it is being
considered by the FDA in the treatment of Post-traumatic stress disorder.
It is also being evaluated for possible usages in palliative care.
Norepinephrine and Dopamine
Reuptake Inhibitors (NDRIs)
These compounds inhibit the uptake of the monoamines
dopamine and norepinephrine into storage vesicles, effectively
increasing their amounts in the brain and causing a stimulating
effect. Many of these compounds are effective ADHD
medications and antidepressants. The most popular and wellknown dopamine and norepinephrine reuptake inhibitor
antidepressant is bupropion (Wellbutrin). Other examples of
NDRIs include MDPV, pyrovalerone, mazindol and pipradrol.
Although these medicines have similar methods of action to
stimulants, they are less popular for abuse (thus not
scheduled) and have an extended release mechanism or a very
long half life. Many NDRIs are also phenethylamines
Cocaine
Cocaine is made from the leaves of the coca shrub, which
grows in the mountain regions of South American countries
such as Bolivia, Colombia, and Peru. In Europe and North
America, the most common form of cocaine is a white
crystalline powder. Cocaine is a stimulant but is not normally
prescribed therapeutically for its stimulant properties,
although it sees clinical use as a local anesthetic, particularly
in ophthalmology. Most cocaine use is recreational and its
abuse potential is high, and so its sale and possession are
strictly controlled in most jurisdictions. Other tropane
derivative drugs related to cocaine are also known such as
troparil and lometopane but have not been widely sold or
used recreationally.
Caffeine
Caffeine is a drug that is found naturally in coffee, tea, and to a small
extent cocoa. It is also found in many soft drinks, particularly energy
drinks. Caffeine stimulates the body, increasing heart rate and blood
pressure, and alertness, making some people feel better and able to
concentrate. In large doses, caffeine is also a mild diuretic. The vast
majority (over 80%) of people in the United States consume caffeine on a
daily basis. As a result, few jurisdictions restrict its sale and use.
Caffeine is also sold in some countries as an isolated drug (as opposed to
its natural occurrence in many foods). It serves as a mild stimulant to
ward off sleepiness and sees wide use among people who must remain
alert in their work (e.g., truck drivers, military members). Some
medications contain caffeine as one of their minor active ingredients,
often for the purpose of enhancing the effect of the main ingredient or
reducing one of its side effects.
Nicotine
Nicotine is an alkaloid found in the nightshade family of plants
(Solanaceae), predominantly in tobacco, and in lower quantities in
tomato, potato, eggplant (aubergine), and green pepper. Nicotine
alkaloids are also found in the leaves of the coca plant. Nicotine
constitutes 0.3 to 5% of the tobacco plant by dry weight, with
biosynthesis taking place in the roots, and accumulates in the leaves. It
is a potent nerve poison and is included in many insecticides. The
primary therapeutic use of nicotine is in treating nicotine dependence
in order to eliminate smoking with its risks to health.
In very low concentrations, nicotine acts as a stimulant, and it is one of
the main factors responsible for the dependence-forming properties of
tobacco smoking. Although pure nicotine is noncarcinogenic, its
presence may inhibit the body's ability to cull aberrant cells.
Ampakines
Recently, there have been improvements in the area of stimulant
pharmacology, producing a class of chemicals known as ampakines, or
eugeroics, (good arousal). These stimulants tend to increase alertness
without the peripheral (body) effects or addiction/tolerance/abuse
potential of the traditional stimulants. They have minimal effect on sleep
structure, and do not cause rebound hypersomnolence or "come down"
effects. Currently, there are two stimulants in this class being used:
modafinil and adrafinil, marketed as Provigil and Olmifon, respectively.
Modafinil and adrafinil also have some amphetamine like actions, in terms
that they increase dopamine and norepinephrine, but they also have
another mode of action as GABA antagonists. Newer ampakines such as
ampalex and CX717 have been developed but are still in clinical trials and
have not yet been sold commercially. Another compound with similar
effects to these drugs is carphedon, which is sold as a general stimulant in
Russia under the brand name Phenotropil.
Testing Stimulants
The presence of stimulants in the body may be tested by a variety of
procedures. Serum and urine are the common sources of testing material
although saliva is sometimes used. Commonly used tests include
chromatography, immunologic assay and mass spectrometry. Recent chronic
abuse of stimulants can also be detected, with a high level of certainty, after
metabolism has eliminated the presence of any stimulant metabolite from
the body. All stimulants destabilize the action of the hypothalamus on the
pituitary.
Under controlled conditions the hypothalamus secretes thyroid-releasing
hormone (TRH).This then stimulates the pituitary to release thyroidstimulating hormone (TSH). Generally when 1 ampule of TRH (Protirelin) is
injected into a vein, 5-10 ug of TSH is detected in the bloodstream after 20
minutes. The amount of TSH released after a recent history of chronic
stimulant use, is decreased. Usually the level of TSH in such a blood sample
is less than 5 ug. This test is generally accurate even after discontinuance of
the drug several weeks earlier and with a negative drug screen.
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