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Antidepressant
An antidepressant is a medication used primarily in the treatment of
clinical depression. Some examples of antidepressants on the market today
are:
• fluoxetine (Prozac, Sarafem, Fluctin, Fontex, Prodep, Fludep)
• sertraline (Zoloft, Lustral, Apo-Sertral, Asentra, Gladem, Serlift,
Stimuloton)
• venlafaxine (Effexor)
• citalopram (Celexa, Cipramil, Talohexane)
• paroxetine (Paxil, Seroxat, Aropax)
• escitalopram (Lexapro, Cipralex)
• fluvoxamine (Luvox, Faverin)
• duloxetine (Cymbalta)
• bupropion (Wellbutrin)
Anitdepressant
Antidepressants are not thought to produce tolerance, although sudden
withdrawal may produce adverse effects. Antidepressants create little
if any immediate change in mood and require between several days and several
weeks to take effect.
Some antidepressants, notably the tricyclics, are commonly used off-label
in the treatment of neuropathic pain, whether or not the patient is depressed.
Smaller doses are generally used for this purpose, and they often take
effect more quickly.
Many antidepressants also are used for the treatment of anxiety disorders,
and tricyclic antidepressants are used in the treatment of chronic pain
disorders such as Chronic Functional Abdominal Pain (CFAP), Myofacial
Pain Syndrome, and post-herpetic neuralgia.
Antidepressants do not seem to have all of the same addictive qualities
as other substances such as nicotine, caffeine, cocaine, or other stimulants.
There is still controversy on the definition of addiction. Some argue
that antidepressants do not meet the general requirements for the commonly
established view. While some antidepressants may cause dependence and
withdrawal they do not seem to cause uncontrollable urges to increase
the dose due to euphoria or pleasure. For example, if an SSRI medication
is suddenly discontinued, it may produce both somatic and psychological
withdrawal symptoms, a phenomenon known as "SSRI discontinuation
syndrome" (Tamam & Ozpoyraz, 2002). When the decision is made
to stop taking antidepressants it is common practice to “wean”
off of them by slowly decreasing the dose over a period of several weeks.
Antidepressant
It is generally not a good idea to take antidepressants without a prescription.
The selection of an antidepressant and dosage suitable for a certain case
and a certain person is a lengthy and complicated process, requiring the
knowledge of a professional. Certain antidepressants can initially make
depression worse, can induce anxiety, or can make a patient aggressive,
dysphoric or acutely suicidal. In certain cases, an antidepressant can
induce a switch from depression to mania or hypomania, can accelerate
and shorten a manic cycle (i.e. promote a rapid-cycling pattern), or can
induce the development of psychosis (or just the re-activation of latent
psychosis) in a patient with depression who wasn't psychotic before the
antidepressant.
Antidepressant History
Like many psychiatric drugs, antidepressants were discovered by accident.
The first antidepressants, imipramine, a tricyclic, and iproniazid, a
monoamine oxidase inhibitor, were discovered in the 1950s. These drugs
were found to have the side effect of improving the patients' mood. However,
the newer SSRI antidepressants were early examples of rational drug design.
Antidepressant - How they are believed to work
The therapeutic effects of antidepressants are believed to be related
to an effect on neurotransmitters, particularly by inhibiting the monoamine
transporter proteins of serotonin and norepinephrine. Selective serotonin
reuptake inhibitors (SSRIs) specifically prevent the reuptake of serotonin
(thereby increasing the level of serotonin in synapses of the brain),
whereas earlier monoamine oxidase inhibitors (MAOIs) blocked the destruction
of neurotransmitters by enzymes which normally break them down. Tricyclic
antidepressants (TCAs) prevent the reuptake of various neurotransmitters,
including serotonin, norepinephrine, and dopamine. Although these drugs
are clearly effective in treating depression, the current theory still
leaves unanswered questions. For example, concentrations in the blood
build to therapeutic levels in only a few days and begin affecting neurotransmitter
activity immediately. Changes in mood, however, often take four weeks
or more to appear. One explanation holds that the "down-regulation"
of neurotransmitter receptors—an apparent consequence of excess
signaling and a process that takes several weeks—is actually the
mechanism responsible for the alleviation of depressive symptoms. Another
theory, based on recent research published by the National Institutes
of Health in the United States, suggests that antidepressants may derive
their effects by promoting neurogenesis in the hippocampus.
Antidepressant Side effects
Antidepressants can often cause side effects, and an inability to tolerate
these is the most common cause of discontinuing the medication. Sexual
dysfunction is a very common side effect, especially with the SSRI's.
Occasionally the sexual side effects of SSRIs can persistent long after
the medications have been discontinued, sometimes indefinitely. One exception
to this is Wellbutrin (bupropion), which in many cases results in a moderately
increased libido. Some clinicians have found that adding Wellbutrin to
a regimen of SSRI medications can sometimes alleviate some degree of sexual
dysfunction. However, the mechanism of action for Wellbutrin appears to
be unique and quite different from other mood elevators, among these being
a stimulant-like effect and concurrent insomnia, especially in the first
few weeks of use. Moreover, some patients, as seen with most psycho-active
drugs, cannot tolerate it all.
Although recent drugs may have fewer side effects, patients sometimes
report severe side effects associated with their discontinuation, particularly
with Paroxetine. Additionally, a certain percentage of patients do not
respond to antidepressant drugs. Another advantage of some newer antidepressants
is they can show effects within as few as five days, whereas most take
four to six weeks to show a change in mood. However, some studies show
that these medication might be even more likely to result in moderate
to severe sexual dysfunction. However, there are medications in trials
that appear to show an improved profile in regards to sexual dysfunction
and other key side effects.
MAO inhibitors can produce a lethal hypertensive reaction if taken with
foods that contain the amino acid tyramine, such as cheese and wine. Likewise,
lethal reactions to both prescription and over the counter medications
have occurred. Any patient currently undergoing therapy with an MAO inhibiting
medication should be monitored closely by the prescribing physician and
always consulted before taking an over the counter or prescribed medication.
Such patients should also inform emergency room personnel and information
should be kept with one's identification indicating the fact that the
holder is on MAO inhibiting medications. Some doctors even suggest the
use of a medical alert ID bracelet.
Antidepressants often make the mania component of bipolar disorder worse,
and should be used with great care in the treatment of that disorder,
usually in conjunction with mood stabilisers. Their use should be monitored
by a psychiatrist, but in countries such as Britain, New Zealand, and
the United States, primary care physicians are able to prescribe antidepressants
without consulting a psychiatrist.
In particular, it has been noted that the most dangerous period for
suicide in a patient with depression is immediately after treatment has
commenced, as antidepressants may reduce the symptoms of depression such
as psychomotor retardation or lack of motivation before mood starts to
improve. Although this appears to be a paradox, studies indicate the suicidal
ideation is a relatively common component of the initial phases of antidepressant
therapy, and it may be even more prevalent in younger patients such as
pre-adolescents and teenagers. It is strongly recommended that other family
members and loved ones monitor the young patient's behavior, especially
in the first eight weeks of therapy, for any signs of suicidal ideation
or behaviors.
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