Duloxetine is part of a new
class of antidepressants which affect both serotonin and
norepinephrine. The other medicine
in this class is venlafaxine (Effexor). There is
some evidence that these “dual action” antidepressants work
faster and produce a more fuller response than other antidepressants. In addition to depression, duloxetine can
relieve anxiety, chronic pain and urinary incontinence.
So far, duloxetine has not been
found to cause weight gain and has a low rate of sexual side effects. However, since the medicine was just
released in September 2004 (it was studied for several years before its
release), we will need to wait before saying definitively that it is free
of these side effects.
other antidepressants, duloxetine takes
3-6 weeks to work (although some people respond earlier). It does not change who you are, although it may allow
you freedom to develop in ways that depression had prevented. Some people say that they feel more like
their usual self, or are better able to deal with stress, after taking
How does it work?
enhances the transmission of serotonin and norepinephrine in the brain.
Both of these neurotransmitters are involved in depression. Serotonin also relieves anxiety, and
norepinephrine can reduce physical pain.
What types are available and how is it taken?
is designed to be taken twice a day, but studies show that it works just as
well when taken once a day. It is
available in 20, 30 and 60mg tablets. It can be taken morning or
night. Taking it after a meal may
reduce nausea if you experience this side effect.
If you miss a dose, ask yourself
if you are closer to the dose you missed or to your next dose. If you are closer to your next dose, just
wait and take it then, otherwise it’s ok to take the dose you missed.
Capsules: 20, 30, 60mg
Taken 1-2 times a day, from 20-120mg total daily dose.
60 of: 20mg ($185), 30mg ($202); 30 of: 60mg ($104).
How long do I
need to take it?
There are two reasons to take duloxetine: 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 it will
be a personal one.
if I stop it?
needs to be
stopped gradually to prevent withdrawal symptoms. These are flu-like symptoms that are
unpleasant but not dangerous; examples
Dizziness, nausea, lethargy, sensory changes (numbness, tingling,
shock-like feelings), blurred vision, headache, vivid dreams, anxiety.
cannot become addicted to duloxetine.
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 it cause
harm? Should children take it?
Duloxetine 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.
Duloxetine has not been adequately studied in
children. There is currently controversy about whether children and
teenagers should take duloxetine due to concern about suicide on
antidepressants. Click here to learn more about these concerns.
effects can I expect?
Since duloxetine is a new medication (released
September 2004), unexpected side effects are possible and you should call
me if you experience any concerning problems on it. Below are the side effects duloxetine is
known to cause:
side effects are usually mild and often improve over time:
Nausea, vomiting, dry mouth, constipation, diarrhea, decreased appetite,
stomach distress, dizziness, fatigue, insomnia, and headache, tingling or
numbness, sweating, vivid dreams, yawning.
The following side
effects may persist and can be treated or will go away if the medicine is
Decreased sex drive, delayed orgasm, tiredness or low motivation.
Difficulty urinating, blurred vision, excessive sweating
elevations of blood pressure: on average, duloxetine raised systolic blood
pressure (the top number) by 2 mmHg and diastolic (the bottom number) by
of liver enzymes: duloxetine elevated liver enzymes in about 5 in 1,000
side effects indicate that the medicine may need to be stopped; call me if
Agitation, intense mood swings, racing thoughts, insomnia, restless
feelings like you can’t stop moving.
Syndrome: this condition is very
rare with duloxetine but can be more common if it is 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.
reaction is possible with any medication.
Symptoms include the following; stop the medication and call me if
Pounding heartbeat; swelling of the face, throat, tongue, lips, eyes,
hands, feet, ankles, or lower legs; hoarseness; difficulty swallowing or
breathing; hives; rash.
Duloxetine may 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.
Pregnancy and Breast-feeding:
Duloxetine likely passes into breast milk and has not been studied
in pregnancy or breast-feeding. We should talk first if you expect to
become pregnant or breast feed while taking it.
Older adults: Duloxetine
appears safe but has not been adequately studied in older adults..
Medical conditions which require caution
or kidney disease
retention, glaucoma, high blood pressure
has not been studied in people with heart disease or seizures
Below is a
partial list of drug interactions.
Make sure your physician knows all the medications you are taking.
Duloxetine may increase levels of:
Tricyclic antidepressants (e.g. nortriptyline, amitriptyline,
desipramine and imipramine), type 1C antiarrhythmics (e.g., propafenone,
flecainide), phenothiazines (acetophenazine, Tindal, chlorpromazine,
Thorazine, fluphenazine, Prolixin, mesoridazine Serentil, perphenazine,
Trilafon, prochlorperazine, Compazine, promazine, Sparine, promethazine,
Phenergan, thioridazine, Mellaril, trifluoperazine, Stelazine,
triflupromazine, Vesprin, trimeprazine).
Medicines that can increase duloxetine levels:
Fluvoxamine (Luvox), fluoxetine
(Prozac), paroxetine (Paxil), cimetidine, ciprofloxacin, enoxacin.
Other medicines than may interact with duloxetine:
(propranolol, metoprolol, timolol), quinidine.
that should be avoided with Duloxetine:
MAOIs (phenelzine, Nardil,
tranylcypromine, Parnate, isocarboxazid, Marplan, procarbazine, Matulane,
out of the reach of children.
away from heat and direct light.
not store in the bathroom, near the kitchen sink, or in other damp
places. Heat or moisture may cause the medicine to break down.
not keep outdated medicine or medicine no longer needed. Be sure that
any discarded medicine is out of the reach of children.
Updated 9/21/4 by Chris Aiken,