One of the newer forms of medication designed to treat mental depression, the brand-name drug Pristiq is classified as an SSNRI, or selective serotonin and norepinephrine reuptake inhibitor. Pristiq, generically named desvenlafaxine, works to raise the activity level of the neurotransmitters norepinephrine and serotonin, the Mayo Clinic reports. Some side effects have been associated with Pristiq use.
When a person starts using Pristiq, the Mayo Clinic reports, the medication may cause some temporary non-serious side effects that most often cease without help from a doctor. Among these types of side effects, Drugs.com lists nausea and vomiting, which may lead to loss of appetite. Most prescription drugs cause these kinds of side effects as the user's body becomes acclimated to the medication. The side effects require medical intervention only if they appear severe or do not end on their own.
Diarrhea and Constipation
The adjustment period for Pristiq also may cause temporary bowel problems. The medication may produce either diarrhea or constipation. Neither problem usually requires medical attention, the Mayo Clinic reports, but Drugs.com recommends consulting a doctor for severe diarrhea or constipation, or if the problems continue.
Antidepressants, Pristiq among them, often cause sexual difficulties. Fortunately, this is a temporary and non-serious side effect, according to Drugs.com. Pristiq may cause a reduction in the normal desire for sexual activities, including sexual intercourse. It also may decrease sexual ability, and prevent the user from achieving orgasm. Pristiq also may cause erection problems in men. Men may not get erections with Pristiq use at first, or they may not maintain erections. They also may take longer to ejaculate, the Mayo Clinic reports.
Drowsiness and Fatigue
Pristiq can induce a feeling of tiredness or drowsiness during the first part of treatment with the medicine. This can feel pervasive, as if the body has become fatigued due to hard work or physical activity. These problems, too, generally cease as the person taking Pristiq becomes accustomed to the medication.