Pristiq Oral Precautions and Side Effects

  • Precautions

    Before taking desvenlafaxine, tell your doctor or pharmacist if you are allergic to it; or to venlafaxine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

    Before using this medication, tell your doctor or pharmacist your medical history, especially of:

    • personal or family history of psychiatric disorders (e.g., bipolar/manic-depressive disorder)
    • personal or family history of suicide attempts
    • bleeding problems
    • glaucoma
    • high blood pressure
    • heart problems (such as chest pain, heart failure, heart attack)
    • history of stroke
    • high cholesterol
    • kidney disease
    • liver disease
    • seizure disorder
    • low sodium in the blood (hyponatremia)

    This drug may make you dizzy or drowsy or cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Avoid alcoholic beverages.

    Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, older adults may be at greater risk for side effects (e.g., bleeding) while using this drug. The elderly are more likely to lose too much salt (hyponatremia), especially if they are also taking "water pills" (diuretics) with this medication.

    Based on information for a similar drug (venlafaxine), this drug may affect growth rate in children. Therefore, caution is advised if this drug is used in children. Monitor your child's height and growth rate. Consult your doctor or pharmacist for more details.

    Use this medication only when clearly needed during pregnancy. It may harm an unborn baby. Also, babies born to mothers who have used this drug during the last 3 months of pregnancy may infrequently develop withdrawal symptoms such as feeding/breathing difficulties, seizures, muscle stiffness, or constant crying. If you notice any of these symptoms in your newborn, tell the doctor promptly.

    Since untreated depression can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss the benefits and risks of using this medication during pregnancy with your doctor.

    This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.

    Side Effects

    See also Warning section.

    Drowsiness, dizziness, nausea, dry mouth, constipation, loss of appetite, weight loss, blurred vision, nervousness, trouble sleeping, or excessive sweating may occur. If any of these effects persist or worsen, tell your doctor promptly.

    Desvenlafaxine may increase blood pressure. Your blood pressure should be checked regularly while you are taking this medication.

    An empty tablet shell may appear in your stool. This is harmless.

    Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

    Tell your doctor immediately if any of these unlikely but serious side effects occur:

    • severe/pounding headache
    • shakiness (tremor)
    • decreased interest in sex
    • changes in sexual ability

    Tell your doctor immediately if any of these rare but very serious side effects occur:

    • chest pain
    • persistent cough
    • shortness of breath
    • black/tarry stools
    • vomit that looks like coffee grounds
    • easy bruising/bleeding
    • seizures
    • change in the amount of urine

    This medication may rarely cause a very serious condition called serotonin syndrome. The risk increases when this medication is used with certain other drugs such as "triptans" used to treat migraine headaches (e.g., sumatriptan, eletriptan), certain antidepressants including SSRIs (e.g., citalopram, paroxetine) and other SNRIs (e.g., duloxetine), lithium, tramadol, tryptophan, or a certain drug to treat obesity (sibutramine). See also Drug Interactions section. Before taking this drug, tell your doctor if you take any of these medications. Serotonin syndrome may be more likely when you start or increase the dose of any of these medications. Seek immediate medical attention if you develop some of the following symptoms:

    • hallucinations
    • restlessness
    • loss of coordination
    • fast heartbeat
    • severe dizziness
    • unexplained fever
    • severe nausea/vomiting/diarrhea
    • twitchy muscles

    A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including:

    • rash
    • itching/swelling (especially of the face/tongue/throat)
    • severe dizziness
    • trouble breathing

    This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

    In the US -

    Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

    In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

    Warning

    Antidepressant medications are used to treat a variety of conditions, including depression and other mental/mood disorders. These medications can help prevent suicidal thoughts/attempts and provide other important benefits. However, studies have shown that a small number of people (especially people younger than 25) who take antidepressants for any condition may experience worsening depression, other mental/mood symptoms, or suicidal thoughts/attempts. Therefore, it is very important to talk with the doctor about the risks and benefits of antidepressant medication (especially for people younger than 25), even if treatment is not for a mental/mood condition.

    Tell the doctor immediately if you notice worsening depression/other psychiatric conditions, unusual behavior changes (including possible suicidal thoughts/attempts), or other mental/mood changes (including new/worsening anxiety, panic attacks, trouble sleeping, irritability, hostile/angry feelings, impulsive actions, severe restlessness, very rapid speech). Be especially watchful for these symptoms when a new antidepressant is started or when the dose is changed.