Medication Guide
Desvenlafaxine (Pristiq) Side Effects and Uses
A plain-language guide to Desvenlafaxine, an SNRI antidepressant. Learn how it helps, what it treats, how to take it and which side effects to know about.
Quick answer. Desvenlafaxine (Pristiq) is an SNRI antidepressant. Common desvenlafaxine side effects include nausea, dizziness, more sweating and trouble sleeping. The rare but serious ones, and when to get help, are listed under desvenlafaxine side effects below. Never stop or change your dose on your own.
How Desvenlafaxine Can Help You
Desvenlafaxine (Pristiq) is the active form of venlafaxine, made into its own medicine. It is an SNRI. It strengthens the brain systems behind mood, energy and stress. This can lift lasting sadness and bring back interest and drive. It can also steady an anxious mood.
One practical plus is its simplicity. For many people, the usual starting dose is also the dose that works. There is no long series of increases.
The body does not need to convert it the way it converts venlafaxine. So levels are more predictable from person to person. Early changes often show up within one to two weeks. Full benefit usually builds over four to eight weeks. Your prescriber checks your progress and blood pressure along the way.
Uses for Desvenlafaxine
- Major depressive disorder in adults
- Menopausal hot flashes (off-label)
- Generalized anxiety disorder (off-label)
- Social anxiety disorder (off-label)
- Panic disorder (off-label)
How to Take Desvenlafaxine
Your prescriber decides your dose, based on your kidney function, other medicines and response. It comes only as an extended-release tablet. Take it once a day at about the same time, with or without food. Swallow it whole. Do not crush, chew or split it. You may sometimes see the empty tablet shell in your stool, which is normal.
Missed a dose? Take it when you remember, unless the next dose is close. Then skip it and do not double up. Like other SNRIs, desvenlafaxine should never be stopped suddenly. That can cause dizziness, nausea, irritability and brain zaps. Follow your prescriber's taper plan whenever the dose goes down or stops.
Desvenlafaxine Side Effects
Common Side Effects
- Nausea, mostly in the first week
- Dizziness
- More sweating
- Trouble sleeping
- Dry mouth
- Constipation
- Lower appetite
- Sexual side effects, such as lower desire or delayed orgasm
Serious: Get Medical Help Promptly
- New or worse suicidal thoughts, mostly in people under 25 (boxed warning)
- Higher blood pressure
- Serotonin syndrome, with agitation, fever, fast heartbeat or stiff muscles
- Unusual bleeding or bruising
- Low sodium (hyponatremia), mostly in older adults
- Mania, with a very high or irritable mood
Pristiq Generic Name and Forms
The generic name for Pristiq is desvenlafaxine. The form in Pristiq is called desvenlafaxine succinate. Generic versions are widely available and contain the same active medicine. It comes only as an extended-release tablet, in more than one strength.
Desvenlafaxine is an SNRI. It has little effect on histamine and acetylcholine. Those receptors cause much of the sleepiness, dry mouth and constipation of older drugs, such as tricyclics.
How Desvenlafaxine Leaves the Body
Desvenlafaxine is cleared mostly through the kidneys and relies little on liver enzymes. So it has fewer enzyme-based drug interactions than many antidepressants. People with kidney disease may need a different dose. Your prescriber may ask about recent lab work.
Its half-life is about 11 hours. That is long enough for once-a-day use. But it is short enough that missed doses can be felt. A phone alarm or a weekly pill box can help you stay on track. Missing several doses in a row can bring dizziness, nausea or irritability. Tell your prescriber if doses are being missed.
Pristiq for Depression and Anxiety
Desvenlafaxine is FDA approved for one condition, major depressive disorder in adults. It is not approved for children or teens. It is also not FDA approved for anxiety disorders. Depression and anxiety often occur together. Anxiety that comes with depression may ease as mood improves.
Your prescriber may use it off-label for anxiety when there is a good reason. Pristiq dosage is personal. Do not change the dose yourself. Do not split tablets to make your own dose. Learn about medication management by telehealth in California.
Interactions and Safety to Know About
Desvenlafaxine must never be combined with an MAOI antidepressant, linezolid or IV methylene blue. Other drugs that raise serotonin, such as triptans, tramadol and St. John's wort, add to the risk of serotonin syndrome. Aspirin, NSAIDs and blood thinners raise bleeding risk. Alcohol is best avoided.
Tell your prescriber about high blood pressure, heart disease, glaucoma and seizures. Also share any history of bipolar disorder. It can raise cholesterol levels in some people, so labs may be checked. Like all antidepressants, it has a boxed warning. It covers suicidal thoughts in young people. If you are thinking about harming yourself, call or text 988, or call 911.
Is Desvenlafaxine Right for You?
Only a full evaluation with a prescriber can tell you if Desvenlafaxine fits your symptoms, history and goals. Harpal Singh, PMHNP-BC offers psychiatric evaluations and ongoing medication management by telehealth anywhere in California.
SCHEDULE AN APPOINTMENT CALL (888) 457-8124
Related Medication Guides
Other guides in the same group, written the same simple way. Being in one group does not mean you can swap one medicine for another.
- Vilazodone (Viibryd), SSRI and serotonin partial agonist antidepressant
- Vortioxetine (Trintellix), Serotonin modulator antidepressant
- Amitriptyline (Elavil), Tricyclic antidepressant (TCA)
- Bupropion (Wellbutrin XL), Atypical antidepressant (norepinephrine-dopamine reuptake inhibitor)
- Citalopram (Celexa), SSRI antidepressant
- Doxepin (Silenor), Tricyclic antidepressant (TCA)
FAQ
Questions About Desvenlafaxine
What is the generic name for Pristiq?
The generic name for Pristiq is desvenlafaxine. The salt form in the brand is desvenlafaxine succinate. Generic desvenlafaxine extended-release tablets are widely available.
How is desvenlafaxine different from venlafaxine (Effexor)?
Desvenlafaxine is the compound your body turns venlafaxine into. Taking it directly skips that step, so levels are more even from person to person. It also often works without many dose changes.
Why doesn't my dose need to be increased over time?
In studies, higher doses did not clearly work better than the usual dose for most people with depression, and they added side effects. That is why the dose often stays the same. Your prescriber may still adjust it based on your response.
Is Pristiq good for anxiety?
Pristiq is FDA approved for depression, not for anxiety disorders. Anxiety that comes with depression may improve as mood improves. If anxiety is your main concern, your prescriber can explain whether Pristiq or a medicine approved for anxiety is the better fit.
Can Pristiq make you sleepy or keep you awake?
Both can happen. Trouble sleeping and drowsiness are each listed as side effects of desvenlafaxine. Tell your prescriber which one you notice, since the plan may change based on how it affects your sleep.
Can I cut a Pristiq tablet in half?
No. Pristiq is an extended-release tablet and must be swallowed whole. Cutting, crushing or chewing it can release too much medicine at once. If you need a different strength, ask your prescriber.
I saw my tablet in the toilet. Did the medicine work?
Yes. The tablet has a shell that releases the medicine as it moves through your gut. The empty shell then passes in the stool. This is expected and does not mean the dose was missed.
Will desvenlafaxine affect my blood pressure?
Like other SNRIs, it can raise blood pressure a little in some people. Your prescriber checks it from time to time. Many people see little or no change.
What if Pristiq does not seem to be working?
Full benefit often takes several weeks, so give it time unless side effects are hard to manage. If you still feel stuck, tell your prescriber rather than changing the dose yourself. If you are thinking about harming yourself, call or text 988, or call 911.
How do I stop desvenlafaxine safely?
Only with a plan from your prescriber. Stopping suddenly can cause dizziness, nausea, irritability and brain zaps. A slow taper, sometimes with in-between steps, makes stopping much more comfortable.