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Selective
Serotonin Reuptake Inhibitors (SSRIs) include fluoxetine (prozac),
paroxetine (paxil), fluvoxamine (luvox), sertraline (zoloft), citalopram
(celexa), and escitalopram (lexapro). Although classified as
antidepressants, SSRIs also treat generalized anxiety disorder,
post-traumatic stress disorder, social phobia, panic disorder, obsessive-compulsive
disorder, bulemia and other conditions. Their release in 1988 was a major
advancement in the treatment of depression because many people who could
not tolerate the side effects of older antidepressants were now able to
take these.
How can SSRIs
help me?
How they will
help you depends on your condition. In general, they reduce anxiety and
depression by returning serotonin to its normal levels in the brain.
Sometimes chronic stress can lower serotonin and cause those symptoms,
other times serotonin falls for no clear reason. In either case, SSRIs can help.
SSRIs
do not work immediately. It usually takes 3-6 weeks to see their effects,
although some people do respond sooner.
They
do not change who you are, although they may allow you freedom to develop
in ways that those emotions had prevented.
Some people say that they feel more like their usual self, or are
better able to deal with stress, after taking them. New research shows that SSRIs can prevent
the damaging effects that stress and depression have on brain cells.
Are there
differences between them?
Most evidence suggests that all SSRIs are
equally effective for the conditions mentioned above. It is also known that people who do not
respond well to one SSRI are likely to benefit from a different one, but so
far there is no way to tell in advance which will work best for you. On average all SSRIs have the same side
effects, but switching to a different SSRI can sometimes help if you have
troublesome effects on one.
Sometimes you will see an SSRI advertised for
a specific condition, such as Zoloft for social phobia, while generic SSRIs
go unadvertised. The reasons for
this have more to do with marketing than with scientific evidence; go to www.aikenmd.com/ads.htm to learn more abou this issue.
There
are a few important differences between the compounds. The older SSRIs (fluoxetine, prozac;
paroxetine, paxil; fluvoxamine, luvox) are now available in generic form,
which also means you won't see advertisements for these. While most SSRIs
will last 1-3 days in your blood after taking them, fluoxetine (prozac)
lasts longer (up to 7 days) and paroxetine (paxil) goes out quickly (less
than 1 day). This can lead to
unpleasant withdrawal symptoms if paroxetine is stopped abruptly. Paroxetine is also available in a
"controlled-release" (CR) form, which provides a slight
improvement in side effects over regular paxil but does not relieve these
withdrawal effects. Fluoxetine
(prozac) is available in a weekly tablet.
Citalopram (Celexa) is also available as a more pure compound called
escitalopram (Lexapro) which provides a slight benefit in side effects
(citalopram is a medicine with a right and left half; lexapro uses only the
half which treats depression). The
SSRIs also differ in how they interact with other medications you may be
taking.
The
following table summarizes the available SSRIs:
|
name
|
sizes
|
generic
|
|
Fluoxetine (Prozac, Sarafem)
|
10, 20, 40mg capsules, tablets or liquid.
|
Y
|
|
Fluoxetine (Prozac Weekly)
|
90mg capsule
|
N
|
|
Paroxetine (Paxil)
|
10, 20, 30, 40mg tablet
|
Y
|
|
Paroxetine CR (Paxil CR)
|
12.5, 25, 37.5mg capsules
|
N
|
|
Fluvoxamine (Luvox)
|
25, 50, 100mg tablets
|
Y
|
|
Sertraline (Zoloft)
|
25, 50, 100mg tablets or liquid
|
N
|
|
Citalopram (Celexa)
|
10, 20, 40mg tablets or liquid
|
N
|
|
Escitalopram (Lexapro)
|
10, 20mg tablets or liquid
|
N
|
How long do I
need to take it?
There are two
reasons to take SSRIs: to treat current symptoms and to prevent the return
of symptoms. These two reasons will
be different in each condition, and in many cases the decision to continue
or stop an SSRI will be a personal one.
What happens
if I stop it?
Most SSRIs need to be stopped gradually to prevent
withdrawal symptoms. These are
flu-like symptoms that are unpleasant but not dangerous; examples include:
•
Dizziness, nausea, lethargy, sensory changes (numbness, tingling,
shock-like feelings), blurred vision, headache, vivid dreams, anxiety.
You
cannot become addicted to SSRI medications.
In other words, if you stop the medicine, you will not crave it or
be more likely to have depression or anxiety than before. In fact, treatment, either with psychotherapy
or medication, allows the brain to reorganize itself in ways that help
prevent future symptoms.
Can they cause
harm? Should children take them?
SSRIs may worsen certain psychiatric conditions, such
as bipolar disorders (“manic-depression”). If you notice these
signs while taking them, call me:
•
Feeling “high”, speeded up, giddy or “too happy”;
decreased need for sleep, paranoid feelings, hyperactivity, racing
thoughts, high anxiety or irritability, talking fast.
People may also feel worse on SSRIs
because of side effects (see below). For example, although SSRIs usually relieve anxiety, anxiety is also a rare
side effect.
There is currently controversy about whether children
and teenagers should take SSRIs due to concern
about suicide on them. Click here to learn more.
What side
effects can I expect?
The following
side effects are usually mild and often improve over time:
Nausea, vomiting, constipation, diarrhea, stomach distress, dry mouth,
dizziness, headache, palpitations, tingling or numbness, sweating,
drowsiness, vivid dreams, anxiety, yawning, blurred vision.
The following
side effects may persist and can be treated or will go away if the medicine
is stopped:
Decreased sex drive, delayed orgasm, tiredness or low motivation.
SSRIs have mild blood-thinning effects, so
you may notice increased menstrual flow or other bleeding. You may need to stop them if you undergo
surgery.
The following side
effects indicate that the medicine may need to be stopped; call me if they
occur:
Agitation, intense mood swings, racing thoughts, insomnia, restless
feelings like you can’t stop moving.
Serotonin
Syndrome: this condition is very
rare with SSRIs but can be more common if they
are taken with other antidepressants or with lithium, tryptophan,
buspar, or St. John’s Wort. It is caused by too much serotonin in the
brain. Symptoms include fever,
muscle jerks, diarrhea, sweats, racing heart,
stomach pain, confusion and mood swings.
If this occurs, stop the medication and call me or go to your local
emergency room.
An allergic
reaction is possible with any medication.
Symptoms include the following; stop the medication and call me if
these occur:
Pounding heartbeat; swelling of the face, throat, tongue, lips, eyes,
hands, feet, ankles, or lower legs; hoarseness; difficulty swallowing or
breathing; hives; rash.
Precautions
Make sure I know of any medical problems you have or
if you are breast feeding or planning to become pregnant.
SSRIs can rarely make you
drowsy. Do not drive a car or operate machinery until you know how this
drug affects you. Remember that alcohol and other medications can add to
the drowsiness caused by this drug.
Plan to avoid unnecessary or prolonged exposure to
sunlight and to wear protective clothing, sunglasses, and sunscreen. Paroxetine may make your skin sensitive to sunlight.
Drug Interactions
These
vary for each SSRI; talk to me about other medicines you are taking. You can check the following link to look
up specific interactions, or speak with your doctor or pharmacist:
Index of
Drug Information
Although
alcohol does not have dangerous interactions with SSRIs,
drinking too much can prevent them from working.
Do not
take Saint John’s Wort with SSRIs; this can cause Serotonin Syndrome (see above)
and other interactions.
Do note
take MAOI antidepressants (phenelzine, Nardil, tranylcypromine, Parnate, isocarboxazid, Marplan, procarbazine, Matulane, selegiline, Eldepryl) with SSRIs.
What should I do if I forget a dose?
Take the
missed dose as soon as you remember it. However, if it is almost time for
the next dose, skip the missed dose and continue your regular dosing
schedule. Do not take a double dose to make up for a missed one. Do not
take more than the prescribed daily amount in 24 hours.
What storage conditions are needed for this medicine?
- Keep
out of the reach of children.
- Store
away from heat and direct light.
- Do
not store in the bathroom, near the kitchen sink, or in other damp
places. Heat or moisture may cause the medicine to break down.
- Do
not keep outdated medicine or medicine no longer needed. Be sure that
any discarded medicine is out of the reach of children.
Updated 6/25/4 by Chris Aiken,
M.D.
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