What is desvenlafaxine (Pristiq), and how does it work (mechanism of action)?
Desvenlafaxine is an oral drug that is used for
It is in a class of
antidepressant drugs called selective serotonin and norepinephrine reuptake
inhibitors (SNRI); a class that also contains
duloxetine (Cymbalta). (Desvenlafaxine is an active metabolite of
venlafaxine, that is, it is a product of venlafaxine that is manufactured by the
body from venlafaxine.) Desvenlafaxine affects neurotransmitters, the chemicals
that nerves within the brain make and release in order to communicate with each
other. Neurotransmitters either travel across the space between nerves and
attach to receptors on the surface of nearby nerves or they attach to receptors
on the surface of the nerves that produced them, to be taken up by the nerve and
released again (a process referred to as re-uptake).
Many experts believe that an imbalance among neurotransmitters is the cause
of depression. Serotonin and norepinephrine are two neurotransmitters released
by nerves in the brain. Desvenlafaxine works by preventing the reuptake of
serotonin and epinephrine by nerves after they have been released. Since uptake
is an important mechanism for removing released neurotransmitters and
terminating their actions on adjacent nerves, the reduced uptake caused by
desvenlafaxine increases the effect of serotonin and norepinephrine in the
brain. The FDA approved desvenlafaxine in February 2008.
What brand names are available for desvenlafaxine (Pristiq)?
Is desvenlafaxine (Pristiq) available as a generic drug?
GENERIC AVAILABLE: Yes
Do I need a prescription for desvenlafaxine (Pristiq)?
What are the side effects of desvenlafaxine (Pristiq)?
Desvenlafaxine can cause
appetite. Increased blood pressure can occur and should be monitored.
Seizures have been
reported. Sexual dysfunction (decreased sex drive and delayed orgasm and
ejaculation) has been associated with desvenlafaxine. Desvenlafaxine and other
SNRIs may increase the risk of gastrointestinal bleeding.
Some patients may experience withdrawal reactions upon stopping
desvenlafaxine. Symptoms of withdrawal include anxiety, nausea, nervousness, and
insomnia. The dose
of desvenlafaxine should be gradually reduced when therapy is discontinued to
prevent symptoms of withdrawal.
Antidepressants increased the risk of
suicidal thinking and behavior (suicidality)
in short-term studies in children and adolescents with depression and other
psychiatric disorders. Anyone considering the use of desvenlafaxine or any other
antidepressant in a child or adolescent must balance this risk with the clinical
need. Patients who are started on therapy should be closely observed for
clinical worsening, suicidality, or unusual changes in behavior.
What is the dosage for desvenlafaxine (Pristiq)?
The recommended dose of desvenlafaxine is 50 mg daily, with or
without food. Tablets should be taken whole and should not be crushed, divided,
chewed, or dissolved. Doses greater than 50 mg are not more effective but cause
more side effects.
Which drugs or supplements interact with desvenlafaxine (Pristiq)?
All SNRIs, including desvenlafaxine, should not be taken with any of the monoamine oxidase inhibitor (MAOI) class of antidepressants, for example, isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), selegiline (Eldepryl), and procarbazine (Matulane) or other drugs that inhibit monoamine oxidase [for example, linezolid (Zyvox)]. Such combinations may lead to confusion, high blood pressure, tremor, hyperactivity, coma, and death. Desvenlafaxine should not be administered within 14 days after stopping MAOIs and MAOIs should not be administered within 7 days of stopping desvenlafaxine.
Similar reactions may occur if desvenlafaxine is combined with other SNRIs, selective serotonin reuptake inhibitors (for example, fluoxetine [Prozac] or paroxetine [Paxil]) or other drugs that increase serotonin in the brain, for example, tryptophan, St. John's wort, meperidine (Demerol) or tramadol (Ultram).
SNRIs may increase the effect of warfarin (Coumadin), leading to excessive bleeding. Warfarin therapy should be monitored more frequently in patients who are also taking desvenlafaxine. Combining SNRIs with aspirin, nonsteroidal antiinflammatory drugs (NSAIDs) or other drugs that affect bleeding may increase the likelihood of upper gastrointestinal bleeding.
Ketoconazole (Nizoral, Extina, Xolegel, Kuric) may reduce the breakdown of desvenlafaxine, therefore increasing concentrations of desvenlafaxine in the body and the risk of adverse effects. Desvenlafaxine may reduce the concentration of midazolam (Versed).
Is desvenlafaxine (Pristiq) safe to take if I’m pregnant or breastfeeding?
Desvenlafaxine is secreted in breast milk. Mothers who are
taking desvenlafaxine should discuss with their doctor whether to not
or to discontinue desvenlafaxine.
What else should I know about desvenlafaxine (Pristiq)?
What preparations of desvenlafaxine (Pristiq) are available?
Tablets (extended release): 50 and 100 mg
How should I keep desvenlafaxine (Pristiq) stored?
Tablets should be kept at room temperature, 20 C and 25 C (68
F and 77 F).