Get emergency medical help if you have signs of an allergic reaction to Pristiq: skin rash or hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Report 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.
Call your doctor at once if you have:
a seizure (convulsions);
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 levels of sodium in the body - headache, confusion, severe weakness, memory problems, feeling unsteady, hallucinations.
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 Pristiq 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.
 Pristiq side effects (more detail)
