Pristiq (desvenlafaxine) for anxiety: What to know

If you’re one of 31% of adults affected by anxiety or another mental health issue, you’re likely aware that a number of medications are available for helping to manage your symptoms. One of those is the antidepressant Pristiq.  

Psychiatrists prescribe Pristiq “off-label” for anxiety, meaning that, while it’s not FDA-approved to treat anxiety, clinical experience and a number of studies have demonstrated its efficacy. Maybe you’ve recently started taking Pristiq, or you’re wondering if it might be an option for you. Whatever the case, read on to learn more about how it works, what its side effects include, and more.

How does Pristiq work?

Pristiq is the brand name for desvenlafaxine, an SNRI (serotonin-norepinephrine reuptake inhibitor). That means that it works by increasing the levels of two important neurotransmitters, serotonin and norepinephrine, in certain parts of the brain.

Serotonin affects your mood, appetite, and sleep, while norepinephrine affects your alertness and attention. Usually after these chemicals carry out their functions they’re reabsorbed by nerve cells. But SNRIs stop that from happening so there are higher amounts of them active in your brain, ultimately leading to a lessening of your symptoms.  

Other examples of SNRIs treatment options include Effexor (venlafaxine) and Cymbalta (duloxetine).  

What conditions does it treat?

Pristiq received FDA approval for the treatment of major depressive disorder (MDD) in 2008. Notably, it’s not approved for children–adults only—but some studies have found it to be effective regarding treatment-resistant symptoms of depression.  

To learn more about other mental health conditions, check out our articles on social anxiety disorder, bipolar disorder, and panic disorder.

What’s the Pristiq dosage for anxiety?

If you are prescribed desvenlafaxine, you’ll find that it comes in an extended-release tablet, which allows the medication to continue working throughout the day. Pristiq is available in 25mg, 50mg, and 100mg tablets, with the maximum dose being 400mg. As a general rule, clinicians tend to prescribe the 50mg tablet for once-daily use, with or without food, throughout treatment, as higher doses haven’t proven to be significantly more effective and may result in more adverse effects.

The 25mg dose, meanwhile, is sometimes prescribed to help wean patients off the medication.  This amount is also given to patients who are new to taking medicine. Some patients find it easier to handle the 25 mg amount because it has fewer side effects compared to the 50 mg amount.

As with any medication, your clinician will assess your overall health, as well as the potential impact of any other medications you may be taking, before prescribing Pristiq.

How long does it take Pristiq to work for anxiety?

Pristiq can begin lowering anxiety symptoms in as little as one week, according to one clinical study. Generally, you’ll start to feel the full effects after taking it for eight weeks. If it hasn’t started working, it’s important not to stop taking it. It can take time for your body to get used to medication and for it to start working. Plus, stopping medication abruptly can lead to some uncomfortable symptoms. SNRIs like Pristiq are known for discontinuation issues (withdrawal symptoms).

If you’ve been taking Pristiq regularly and don’t see relief from your symptoms, reach out to your doctor. They can help modify your dose and try you on another anxiety medication.  

Side effects of Pristiq

Like many antidepressants, Pristiq can cause a range of side effects. When they do occur, they tend to happen in the first week and go away quickly. If you’re worried about a specific side effect, don’t hesitate to let your doctor know.

Most common side effects

• Nausea  
• Headaches  
• Excessive sweating
• Dry mouth
• Dizziness  
• Insomnia  
• Constipation  
• Fatigue
• Drowsiness
• Decreased appetite
• Sexual dysfunction

Less common, more serious side effects

• Increased blood pressure
• Tremors
• Tachycardia, or elevated heart rate
• Jitteriness
• Irritability  
• Diarrhea
• Vomiting  

For many antidepressants, including Pristiq, the most important side effect to be aware of is a potential increased risk of suicidal thoughts in young adults during their first months taking the medication.

If you have specific concerns about the effects of desvenlafaxine, be sure to consult a qualified clinician. If you’re not sure where to start, consider taking Talkiatry’s quick assessment. We’ll work to match you with a psychiatrist who can answer your questions.

What to know before taking it

Before prescribing you Pristiq, your doctor will look at all the other medications you take, as well as your general health, to determine if it’s right for you. Let your doctor know if, for example, you have any medical conditions like high blood pressure, heart problems, or are pregnant or may become pregnant. Your clinician can help you weigh the risks and benefits of taking Pristiq during pregnancy and while breastfeeding, as a relatively small portion of the medication can find its way into breast milk.

Also let them know if you take other amphetamines, lithium, aspirin or other NSAIDs, or opioids. In fact, tell your clinician about every over-the-counter and prescribed medication and supplement you take so they can provide the best possible treatment and make you aware of any potential drug interactions.

In particular, your physician will want to know if you’re currently taking (or have very recently taken) other antidepressants or medications that increase levels of serotonin, including MAOIs (monoamine oxidase inhibitor), SSRIs, and St. John’s wort. Pairing an MAOI with Pristiq may cause a serious, potentially life-threatening condition called serotonin syndrome. Additionally, you shouldn’t take Pristiq if you’re taking the antibiotic linezolid or the intravenous drug methylene blue.

Is Pristiq good for my anxiety?  

What is the best medication for anxiety? The answer is that there isn’t one. Or, rather, there isn’t one specific one that’s optimal for every person with anxiety. In many ways, Pristiq is like a number of other antidepressants. But different people have different reactions to prescription medications, and Pristiq is no different. It might be right for you, or it might not, depending on your health, medical history, and other personal factors. You and your doctor will review these details together to decide what will work best for you.

If you have an anxiety disorder, know that getting better is possible. The first step to getting any sort of treatment is to get a proper diagnosis. You can do so by taking Talkiatry’s quick assessment. We’re a national psychiatry practice that provides in-network virtual care for various mental health conditions and we’ll use your answers to ensure that we’re a good fit for each other and then match you with a doctor.

The information in this article is for education and informational purposes only and should never be substituted for medical advice, diagnoses, or treatment. If you or someone you know may be in danger, call 911 or the National Suicide and Crisis Lifeline at 988 right away.