warnings

What is the most important information I should know about Pristiq (Desvenlafaxine)?

You should not use this medicine if you are allergic to desvenlafaxine or venlafaxine (Effexor).

Do not use desvenlafaxine within 7 days before or 14 days after you have used an MAO inhibitor, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, or tranylcypromine. A dangerous drug interaction could occur.

Tell your doctor if you also use stimulant medicine, opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson's disease, migraine headaches, serious infections, or prevention of nausea and vomiting. An interaction with desvenlafaxine could cause a serious condition called serotonin syndrome.

Tell your doctor if you have ever had:

heart disease, high blood pressure, high cholesterol, or a stroke;
bipolar disorder (manic depression);
depression, suicidal thoughts;
liver or kidney disease;
glaucoma;
seizures or epilepsy;
sexual problems;
lung or breathing problems;
a bleeding or blood clotting disorder; or
low levels of sodium in your blood.

People with depression or mental illness may have thoughts about suicide. Some young people may have increased suicidal thoughts when first starting a medicine to treat depression. Stay alert to changes in your mood or symptoms. Your family or caregivers should also watch for sudden changes in your behavior.

Taking this medicine during pregnancy could harm the baby, but stopping the medicine may not be safe for you. Do not start or stop desvenlafaxine without asking your doctor.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of desvenlafaxine on the baby.

Ask a doctor if it is safe to breastfeed while using this medicine.

Not approved for use by anyone younger than 18 years old.

Side Effects

What are the side effects of Pristiq (Desvenlafaxine)?

Get emergency medical help if you have signs of an allergic reaction: skin rash or hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Tell your doctor right away if you have new or sudden changes in mood or behavior, including new or worse depression or anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, more active or talkative, or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have:

a seizure;
easy bruising or bleeding (nosebleeds, bleeding gums), blood in your urine or stools, coughing up blood;
blurred vision, eye pain or swelling, or seeing halos around lights;
cough, chest discomfort, trouble breathing; or
low blood sodium--headache, confusion, problems with thinking or memory, weakness, feeling unsteady.

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Common side effects may include:

dizziness, drowsiness, anxiety;
increased sweating;
nausea, decreased appetite, constipation;
sleep problems (insomnia); or
decreased sex drive, impotence, or difficulty having an orgasm.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Pregnancy & Breastfeeding

Can I take Pristiq (Desvenlafaxine) if I’m pregnant or breastfeeding?

Risk cannot be ruled out

Based on FDA pregnancy categories

Taking this medicine during pregnancy could harm the baby, but stopping the medicine may not be safe for you. Do not start or stop desvenlafaxine without asking your doctor.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of desvenlafaxine on the baby.

Ask a doctor if it is safe to breastfeed while using this medicine.

Dosage Guidelines & Tips

How to take Pristiq (Desvenlafaxine)?

Use Pristiq (Desvenlafaxine) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Take desvenlafaxine with water at the same time each day, with or without food.

Swallow the tablet whole and do not crush, chew, or break it.

Your symptoms may not improve for several weeks.

Your blood pressure will need to be checked often.

Tell your doctor if you have any changes in sexual function, such as loss of interest in sex, trouble having an orgasm, or (in men) problems with erections or ejaculation. Some sexual problems can be treated.

Do not stop using desvenlafaxine suddenly, or you could have unpleasant symptoms (such as agitation, confusion, tingling or electric shock feelings). Ask your doctor before stopping the medicine.

Part of a tablet shell may appear in your stool but this will not make the medicine less effective.

Store at room temperature away from moisture and heat.

What should I do if I missed a dose of Pristiq (Desvenlafaxine)?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.