Pristiq (desvenlafaxine) is an antidepressant in a group of drugs called selective serotonin and norepinephrine reuptake inhibitors (SNRIs). Pristiq affects chemicals in the brain that may become unbalanced and cause depression.
rnPristiq is used to treat major depressive disorder.
rnPristiq may also be used for other purposes not listed in this medication guide.

The health and medical information provided here is for general purposes only and is not a substitute for the expertise and judgment of your physician, or other health care professional. It should not be understood to indicate that the use of this medicine is safe, appropriate or effective for you. Always consult your health care professional before using this, or any other, drug.

You should not take Pristiq if you are allergic to desvenlafaxine or venlafaxine (Effexor), or if you are also using a monoamine oxidase inhibitor (MAOI) such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate). You must wait at least 14 days after stopping an MAOI before you can take Pristiq. After you stop taking Pristiq, you must wait at least 7 days before you start taking an MAOI.
rnYou should not take Pristiq together with venlafaxine (Effexor).
rnYou may have thoughts about suicide when you first start taking an antidepressant such as Pristiq, especially if you are younger than 24 years old. Your doctor will need to check you at regular visits for at least the first 12 weeks of treatment.
rnCall your doctor at once if you have any new or worsening symptoms such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself. It may take several weeks before your symptoms improve. Keep using the medication as directed and tell your doctor if your symptoms do not improve after a few weeks of treatment. Do not stop using Pristiq suddenly, or you could have unpleasant symptoms. Ask your doctor how to avoid these symptoms when you stop using Pristiq.

Get emergency medical help if you have any of these signs of an allergic reaction to Pristiq: skin rash or hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
rnReport any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.
rnCall your doctor at once if you have a serious side effect such as:
rnseizure (convulsions);
rnvery stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out;
rnagitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination;
rnheadache, trouble concentrating, memory problems, weakness, feeling unsteady, confusion, hallucinations, fainting, shallow breathing or breathing that stops;
rnblurred vision, eye pain, or seeing halos around lights;
rncough, chest tightness, trouble breathing; or
rneasy bruising or bleeding (nosebleeds, bleeding gums), blood in your urine or stools, coughing up blood.
rnLess serious Pristiq side effects may include:
rndizziness, drowsiness, tired feeling;
rndry mouth, loss of appetite;
rnconstipation;
rnsleep problems (insomnia);
rnmild headache; or
rndecreased sex drive, impotence, or difficulty having an orgasm.

Take Pristiq exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.
rnTake this medicine with a full glass of water. Pristiq can be taken with or without food. Try to take the medicine at the same time each day. Do not crush, chew, break, or dissolve the extended-release tablet. Swallow the pill whole. Breaking or dissolving the pill may cause too much of the drug to be released into the body at one time.
rnThe Pristiq tablet is made with a shell that is not absorbed or melted in the body. Part of the tablet shell may appear in your stool. This is a normal side effect of Pristiq and will not make the medication less effective.
rnIt may take several weeks before your symptoms improve. Keep using the medication as directed and tell your doctor if your symptoms do not improve after a few weeks of treatment. Do not stop using Pristiq suddenly, or you could have unpleasant symptoms. Ask your doctor how to avoid these symptoms when you stop using Pristiq.
rnYour blood pressure will need to be checked often. Visit your doctor regularly.
rnStore Pristiq at room temperature away from moisture and heat.