Side Effects of Pristiq: A Guide to What’s Normal, and What’s Not

Quick Answer: Pristiq (desvenlafaxine) is an SNRI antidepressant that helps depression by balancing brain chemicals. Common side effects like nausea (22%), dizziness (13%), and sweating (10%) are usually mild and temporary. Serious side effects are rare but include increased blood pressure, suicidal thoughts in young adults, and serotonin syndrome. Most people tolerate Pristiq well, especially at the recommended 50mg dose.

Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with your healthcare provider about medication decisions and never stop or change your medication without professional guidance.

Starting a new antidepressant can feel overwhelming, especially when you’re already dealing with depression or anxiety. If your doctor has prescribed Pristiq, you might be wondering what side effects to expect and which ones need immediate attention. Let’s walk through what may be helpful regarding Pristiq’s side effects in a clear, supportive way.

Understanding Pristiq and how it works

Pristiq (desvenlafaxine) is a serotonin-norepinephrine reuptake inhibitor (SNRI), a class of antidepressants that enhance the availability of the neurotransmitters serotonin and norepinephrine in the brain [1]. By inhibiting their reuptake, Pristiq increases synaptic concentrations of these mood-regulating chemicals, which contributes to the reduction of depressive symptoms.

Pristiq is approved by the U.S. Food and Drug Administration (FDA) for the treatment of major depressive disorder (MDD) in adults [2]. Unlike some antidepressants that require dose titration, Pristiq is typically initiated and maintained at a therapeutic dose of 50 mg once daily. Clinical trials have shown that increasing the dose above 50 mg does not significantly enhance efficacy but may lead to a higher incidence of adverse effects [3].

A distinguishing feature of Pristiq is its predictable pharmacokinetic profile. Approximately 45% of the drug is excreted unchanged in the urine, reducing reliance on hepatic metabolism. This makes Pristiq a potentially suitable option for patients with mild to moderate hepatic impairment or those taking other medications that may interact with liver enzymes [1].

Common side effects you might experience

Most side effects associated with Pristiq (desvenlafaxine) are mild to moderate in intensity and tend to diminish within the first few weeks of treatment as the body adjusts. In placebo-controlled clinical trials using the standard 50 mg dose, the following side effects were most frequently reported [4]:

• Nausea was the most common, occurring in approximately 22% of patients taking Pristiq versus 10% on placebo. This effect typically peaks within the first week and improves by week two. Taking Pristiq with food may help reduce gastrointestinal discomfort.
  
  
• Dizziness was reported in 13% of patients, compared to 5% on placebo. This is often orthostatic in nature, worsening upon standing, and can be minimized by rising slowly from seated or lying positions.
  
  
• Hyperhidrosis (excessive sweating) occurred in 10% of Pristiq users versus 4% on placebo. Though not medically dangerous, it can be bothersome; wearing breathable clothing and staying in cool environments may help.
  
  
• Other frequently reported side effects include dry mouth (11%), constipation (9%), and insomnia (9%). These symptoms are typically transient and manageable for most individuals [4].

Serious side effects requiring immediate attention

Though rare, certain adverse effects may be serious and warrant immediate medical evaluation:

• Suicidal thoughts or behaviors: As with all antidepressants, Pristiq carries an FDA-mandated black box warning for increased risk of suicidal ideation, particularly in individuals aged 18 to 24. This risk is highest during the first few months of treatment or when the dose is adjusted [5]. Any new or worsening mood symptoms should be promptly reported.
  
  
• Serotonin syndrome: A potentially life-threatening condition that may result from excessive serotonergic activity, especially when combined with other serotonergic agents. Symptoms include agitation, confusion, hallucinations, fever, muscle rigidity, and gastrointestinal distress [6].
  
  
• Sustained hypertension: Clinical studies have shown that 1.3% of patients on 50 mg of Pristiq developed persistent increases in blood pressure, compared to 0.5% on placebo [4]. Blood pressure monitoring is recommended, particularly in individuals with preexisting cardiovascular conditions.
  
  
• Abnormal bleeding: SNRIs may impair platelet function, increasing the risk of bleeding, especially when combined with NSAIDs, aspirin, or anticoagulants. Signs include easy bruising, nosebleeds, or prolonged bleeding [1].
  
  
• Other rare but serious adverse effects include severe allergic reactions, angle-closure glaucoma, hyponatremia (low sodium levels), and seizures in susceptible individuals.

Comparing common and serious side effects

Here’s a helpful comparison table to distinguish between typical side effects and those requiring medical attention:

Common Side Effects (Usually Mild)	Serious Side Effects (Seek Medical Help)
Nausea (22%)	Suicidal thoughts or behavior changes
Dizziness (13%)	Serotonin syndrome symptoms (fever, confusion, rigidity)
Dry mouth (11%)	Sustained high blood pressure
Excessive sweating (10%)	Unusual bleeding or bruising
Constipation (9%)	Severe allergic reactions
Insomnia (9%)	Angle-closure glaucoma (eye pain, vision changes)
Decreased appetite (5%)	Hyponatremia (headache, confusion, weakness)
Fatigue (4%)	Seizures

As always, any new, worsening, or concerning symptoms should be discussed with a healthcare provider to ensure safe and effective use of Pristiq

Managing side effects effectively

Most side effects improve with time, but there are strategies to help you cope while your body adjusts.

For nausea, try taking Pristiq with food or at bedtime. Ginger may also provide natural relief. If nausea persists beyond two weeks, talk to your doctor about anti-nausea medications.

Combat dizziness by staying hydrated, nourished and avoiding sudden position changes. When getting out of bed, sit on the edge for a moment before standing. If dizziness continues, your doctor might check your blood pressure or adjust your dose.

Sleep problems often respond to good sleep hygiene. Establish a regular bedtime routine, avoid screens before bed, and limit caffeine after noon. Some people find taking Pristiq in the morning helps reduce insomnia. Getting morning sunlight is also important for balancing circadian rhythm which can help with regular sleep.

For constipation increase your intake of nutrient fruits and vegetables, drink plenty of water, and stay physically active. Yoga and movement may also be helpful in promoting bowel movements.

Overall, maintaining a healthy lifestyle is key in supporting anxiety and depression, as well as helping your body adjust to a medication. These include sufficient nutrition, sleep, movement, sunlight and nature exposure, as well as meaningful connections, purpose and therapy.

Understanding discontinuation syndrome

One important consideration with Pristiq is discontinuation syndrome, withdrawal-like symptoms that can occur if you stop the medication suddenly. Research shows these symptoms affect many people and can include dizziness, nausea, headache, irritability, and unusual sensations like “brain zaps” [7].

The symptoms typically begin 1-4 days after stopping and can last from a few days to several weeks. That’s why it’s crucial never to stop Pristiq abruptly. Your doctor will create a tapering schedule, often using the 25mg dose to gradually reduce your medication [8].

Interestingly, studies show that even the recommended one-week taper may be too fast for some people. Many patients benefit from slower tapering schedules over several weeks or months [7].

Special considerations for different groups

Pregnancy and breastfeeding: While there’s limited data on Pristiq during pregnancy, the medication does pass into breast milk at low levels (about 6.8% of the maternal dose) [9]. The benefits of treating depression often outweigh potential risks, but this decision requires careful discussion with your healthcare provider.

Older adults: People over 65 may experience more dizziness and are at higher risk for low sodium levels. The good news is that Pristiq doesn’t require dose adjustments for age alone, though kidney function should be monitored [1].

Sexual side effects: While less common than with some antidepressants, sexual side effects can occur. Men may experience erectile dysfunction (3%) or delayed ejaculation (1-5%), while women report these effects less frequently [10]. Many people find these effects improve over time or with management strategies.

Frequently asked questions

How long do side effects last? Most common side effects like nausea and dizziness improve significantly within 2-4 weeks. However, some effects like sweating may persist longer. Your body typically adjusts to the medication within 4-6 weeks.

Will Pristiq cause weight changes? Clinical trials show minimal weight impact. Only 1.6% of patients experienced significant weight loss (≥7% decrease) compared to 0.8% on placebo. Weight gain was equally rare [4].

Can I drink alcohol while taking Pristiq? While Pristiq doesn’t directly interact with alcohol, both substances affect your brain chemistry. Alcohol can worsen depression and increase side effects like dizziness. It’s best to limit or avoid alcohol, especially when starting treatment.

What if I miss a dose? Take your missed dose as soon as you remember, unless it’s almost time for your next dose. Never double up on doses. Missing doses can trigger mild withdrawal symptoms, reinforcing the importance of consistent daily dosing.

Moving forward with confidence

Starting Pristiq represents an important step in managing your depression. While side effects can feel discouraging, remember that most are temporary and manageable. The therapeutic benefits, improved mood, better sleep, increased energy, often become apparent within 4-8 weeks. However, also keep in mind that everyone responds to medications differently. Lifestyle factors also play a key role, as well as bioindividuality.

Keep open communication with your healthcare provider about any side effects you experience. They can help distinguish between normal adjustment symptoms and those requiring intervention.

Remember, you also know your body best. Be attuned to subtle changes and monitor them. Advocate for yourself if you feel like the medication isn’t working for you by talking openly with your doctor and taking care of yourself. The better nourished you are– body and mind– the better medications work, often with fewer side effects.

Not sure if Pristiz is right for you or how to handle its side effects?

Talk to a licensed provider at PsychPlus to get personalized support and treatment recommendations that put your mental health first.

References

[1] Liebowitz MR, Manley AL, Padmanabhan SK, et al. Efficacy, safety, and tolerability of desvenlafaxine 50 mg/day and 100 mg/day in the treatment of major depressive disorder. Curr Med Res Opin. 2008;24(7):1877-1890. https://pubmed.ncbi.nlm.nih.gov/18507895/

[2] Clayton AH, Kornstein SG, Prakash A, et al. Changes in sexual functioning associated with duloxetine, escitalopram, and placebo in the treatment of patients with major depressive disorder. J Sex Med. 2007;4(4):917-929. https://pubmed.ncbi.nlm.nih.gov/17627739/

[3] Boyer P, Montgomery S, Lepola U, et al. Efficacy, safety, and tolerability of fixed-dose desvenlafaxine 50 and 100 mg/day for major depressive disorder in a placebo-controlled trial. Psychopharmacology. 2008;200(3):493-503. https://pubmed.ncbi.nlm.nih.gov/18703933/

[4] Clayton AH, Tourian KA, Focht K, et al. An integrated analysis of the safety and tolerability of desvenlafaxine compared with placebo in the treatment of major depressive disorder. CNS Spectr. 2009;14(4):183-195. https://www.cambridge.org/core/journals/cns-spectrums/article/an-integrated-analysis-of-the-safety-and-tolerability-of-desvenlafaxine-compared-with-placebo-in-the-treatment-of-major-depressive-disorder/333108E6433BBF872F97A62D5AD45B6D

[5] U.S. Food and Drug Administration. (2018). PRISTIQ (desvenlafaxine) extended-release tablets, for oral use. Prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/021992s042lbl.pdf

[6] Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med. 2005;352(11):1112-1120. https://pubmed.ncbi.nlm.nih.gov/15784664/

[7] Fava GA, Gatti A, Belaise C, et al. Withdrawal symptoms after selective serotonin reuptake inhibitor discontinuation: a systematic review. Psychother Psychosom. 2015;84(2):72-81. https://pubmed.ncbi.nlm.nih.gov/25721705/

[8] Rosenbaum JF, Fava M, Hoog SL, et al. Selective serotonin reuptake inhibitor discontinuation syndrome: a randomized clinical trial. Biol Psychiatry. 1998;44(2):77-87. https://pubmed.ncbi.nlm.nih.gov/9646889/

[9] Rampono J, Teoh S, Hackett LP, et al. Estimation of desvenlafaxine transfer into milk and infant exposure during its use in lactating women with postnatal depression. Arch Womens Ment Health. 2011;14(1):49-53. https://pubmed.ncbi.nlm.nih.gov/20960017/

[10] Serretti A, Chiesa A. A meta-analysis of sexual dysfunction in psychiatric patients taking antidepressants. Int Clin Psychopharmacol. 2011;26(3):130-140. https://pubmed.ncbi.nlm.nih.gov/21191308/