Desvenlafaxine XR Side Effects: What You Need to Know

Every medication comes with potential side effects, and Desvenlafaxine XR is no exception. The good news is that most people tolerate it well, and many side effects improve within the first few weeks of treatment. But it's important to know what's normal, what's not, and when to call your doctor.

This guide covers the most common and serious side effects of Desvenlafaxine XR (also sold as Pristiq and Khedezla), based on FDA labeling data.

What Is Desvenlafaxine XR?

Desvenlafaxine XR is a serotonin-norepinephrine reuptake inhibitor (SNRI) approved for the treatment of major depressive disorder (MDD). It's the active metabolite of Venlafaxine (Effexor XR). For a more detailed overview, see our guide on what Desvenlafaxine XR is and how it works.

Common Side Effects

These side effects are the most frequently reported in clinical trials. They usually appear within the first 1 to 2 weeks and often improve as your body adjusts:

• Nausea — The most commonly reported side effect. Taking Desvenlafaxine XR with food can help.
• Dizziness — Usually mild and temporary. Avoid driving until you know how the medication affects you.
• Insomnia — Difficulty falling or staying asleep. Taking your dose in the morning may help.
• Constipation — Increasing fiber and water intake can ease this.
• Excessive sweating (hyperhidrosis) — Common with SNRIs. Wearing breathable clothing and staying hydrated helps.
• Decreased appetite — Some people experience mild weight changes.
• Drowsiness or fatigue — More common in the first week.
• Dry mouth — Sipping water or chewing sugar-free gum can help.
• Sexual dysfunction — This can include decreased libido, erectile dysfunction, delayed ejaculation, and difficulty reaching orgasm. This is one of the more persistent side effects of SNRIs.

Most of these are dose-related, meaning they're more likely at higher doses. The recommended dose of 50 mg/day tends to have fewer side effects than higher doses.

Serious Side Effects

These are less common but require immediate medical attention:

Suicidal Thoughts and Behavior

Desvenlafaxine XR carries an FDA boxed warning about the increased risk of suicidal thinking and behavior, especially in young adults under 25. This risk is highest during the first few months of treatment or when the dose changes. If you or someone you know experiences worsening depression, new or sudden changes in mood, or thoughts of self-harm, contact your doctor immediately or call 988 (Suicide and Crisis Lifeline).

Serotonin Syndrome

This is a rare but potentially life-threatening condition that can occur when Desvenlafaxine XR is combined with other serotonergic medications. Symptoms include:

• Agitation or restlessness
• Rapid heartbeat
• High body temperature
• Muscle twitching or rigidity
• Loss of coordination
• Nausea, vomiting, or diarrhea

Seek emergency medical care immediately if you experience these symptoms. Learn more about drug interactions that can increase this risk.

Increased Blood Pressure

Desvenlafaxine XR can raise blood pressure. Your doctor should monitor your blood pressure regularly, especially when starting or increasing your dose.

Abnormal Bleeding

SNRIs can affect platelet function and increase bleeding risk, particularly if you take blood thinners like Warfarin or NSAIDs like Ibuprofen.

Hyponatremia (Low Sodium)

This is more common in older adults and can cause headache, difficulty concentrating, memory problems, confusion, and weakness. In severe cases, it can lead to seizures.

Other Serious Side Effects

• Angle-closure glaucoma — Sudden eye pain, vision changes, or swelling around the eye
• Seizures — Rare but possible
• Mania or hypomania — Especially in patients with undiagnosed bipolar disorder

Specific Populations

Pregnancy and Breastfeeding

Use of Desvenlafaxine XR in late pregnancy may cause complications in the newborn. The medication is also excreted in breast milk. Talk to your doctor about the risks and benefits if you are pregnant, planning to become pregnant, or breastfeeding.

Older Adults

Elderly patients may be at increased risk for dizziness, orthostatic hypotension (feeling lightheaded when standing), and hyponatremia. Dose adjustments may be needed.

Kidney or Liver Problems

If you have moderate to severe kidney impairment, the maximum recommended dose is 50 mg/day. For liver impairment, the maximum dose is 100 mg/day. Your doctor will adjust your dose based on your specific situation.

How to Manage Side Effects

Here are some general strategies to manage common Desvenlafaxine XR side effects:

• Take it at the same time every day — Consistency helps your body adjust.
• Take it in the morning — This can reduce insomnia.
• Take it with food — This can reduce nausea.
• Stay hydrated — Helps with constipation, dry mouth, and sweating.
• Don't stop suddenly — Abruptly stopping Desvenlafaxine XR can cause withdrawal symptoms including dizziness, nausea, headache, irritability, and "brain zaps" (electric shock sensations). Always taper gradually under your doctor's guidance.
• Talk to your doctor about persistent side effects — If a side effect bothers you for more than 2 to 3 weeks, your doctor may adjust your dose or suggest alternatives. See our guide on alternatives to Desvenlafaxine XR.

When to Call Your Doctor

Contact your doctor or seek emergency care if you experience:

• Suicidal thoughts or behavior changes
• Signs of serotonin syndrome (listed above)
• Unusual bleeding or bruising
• Severe dizziness or fainting
• Seizures
• Severe allergic reaction (rash, swelling, difficulty breathing)
• Manic episodes (racing thoughts, excessive energy, reckless behavior)
• Vision changes or eye pain

Final Thoughts

Most people do well on Desvenlafaxine XR, especially at the recommended 50 mg/day dose. Side effects like nausea and dizziness are common at first but usually improve within a couple of weeks. Serious side effects are rare but important to recognize.

If you're just starting Desvenlafaxine XR, keep in touch with your doctor during the first few weeks, and don't hesitate to reach out if something doesn't feel right. If you need help finding a pharmacy with Desvenlafaxine XR in stock, try Medfinder.