Pristiq XR Drug Interactions You Should Know About

If you're taking Pristiq XR (Desvenlafaxine) — or about to start — it's important to know which medications, supplements, and substances can interact with it. Some interactions are dangerous. Others are manageable with the right precautions.

This guide covers the major and moderate drug interactions for Pristiq XR, plus what to tell your doctor before starting treatment.

How Drug Interactions Work

A drug interaction happens when one substance changes how another works in your body. With Pristiq XR, interactions generally fall into three categories:

1. Serotonin overload — Combining Pristiq XR with other medications that increase serotonin can cause a dangerous condition called serotonin syndrome
2. Increased bleeding risk — Pristiq XR affects platelet function, so combining it with blood thinners or NSAIDs raises bleeding risk
3. Changed drug levels — Some medications can increase Pristiq XR levels in your blood, or Pristiq XR can affect levels of other drugs

Major Drug Interactions (Avoid or Use With Extreme Caution)

MAO Inhibitors — Contraindicated

This is the most dangerous interaction. Do not take Pristiq XR with any MAO inhibitor (MAOI), including:

• Phenelzine (Nardil)
• Tranylcypromine (Parnate)
• Isocarboxazid (Marplan)
• Selegiline (Emsam patch)

You must wait at least 14 days after stopping an MAOI before starting Pristiq XR, and at least 7 days after stopping Pristiq XR before starting an MAOI. The combination can cause life-threatening serotonin syndrome.

Linezolid (Zyvox) and IV Methylene Blue

These medications have MAOI-like properties and can trigger serotonin syndrome when combined with Pristiq XR. If you need either of these, your doctor may temporarily stop Pristiq XR.

Other Serotonergic Medications

Combining Pristiq XR with other drugs that raise serotonin increases the risk of serotonin syndrome. These include:

• SSRIs: Sertraline (Zoloft), Escitalopram (Lexapro), Fluoxetine (Prozac), Paroxetine (Paxil), Citalopram (Celexa)
• Other SNRIs: Venlafaxine (Effexor XR), Duloxetine (Cymbalta)
• Triptans (migraine medications): Sumatriptan (Imitrex), Rizatriptan (Maxalt)
• Tramadol (Ultram) — a pain medication with serotonergic effects
• Fentanyl
• Lithium
• Tryptophan supplements

CYP3A4 Inhibitors

Strong CYP3A4 inhibitors like Ketoconazole (an antifungal) can increase Desvenlafaxine blood levels. Your doctor may need to adjust your dose.

Moderate Drug Interactions

NSAIDs and Blood Thinners

Pristiq XR can increase bleeding risk. Use caution when combining it with:

• NSAIDs: Ibuprofen (Advil, Motrin), Naproxen (Aleve), Aspirin
• Anticoagulants: Warfarin (Coumadin), Apixaban (Eliquis), Rivaroxaban (Xarelto)

If you need regular pain relief, talk to your doctor about safer alternatives like Acetaminophen (Tylenol).

Blood Pressure Medications

Because Pristiq XR can raise blood pressure through its norepinephrine effects, it may reduce the effectiveness of antihypertensive medications. Your doctor should monitor your blood pressure regularly.

CYP2D6 Substrates

At higher doses, Desvenlafaxine is a weak inhibitor of the CYP2D6 enzyme. This can modestly increase levels of medications processed by this enzyme, such as certain antidepressants, antipsychotics, and beta-blockers. This is generally only a concern at doses above 100 mg/day.

Supplements and Over-the-Counter Products to Watch

• St. John's Wort — a popular herbal supplement for mood that increases serotonin. Combining it with Pristiq XR increases serotonin syndrome risk. Avoid this combination.
• Tryptophan (5-HTP) — another serotonin-boosting supplement. Do not take with Pristiq XR.
• NSAIDs (Ibuprofen, Naproxen) — available over the counter and can increase bleeding risk
• Dextromethorphan (DXM) — found in many cough medicines (Robitussin DM, Mucinex DM). Has serotonergic properties and should be used cautiously.

Food and Drink Interactions

Alcohol

Avoid alcohol while taking Pristiq XR. Alcohol can worsen CNS depressant effects including dizziness, drowsiness, and impaired judgment. It can also worsen depression.

Food

There are no significant food interactions with Pristiq XR. You can take it with or without food.

What to Tell Your Doctor

Before starting Pristiq XR, give your doctor a complete list of everything you take, including:

• All prescription medications
• Over-the-counter drugs (including pain relievers and cold medicines)
• Herbal supplements and vitamins
• Recreational substances including alcohol

Don't assume something is too minor to mention. Even common OTC products like Ibuprofen or cough syrup can interact with Pristiq XR.

If another doctor or dentist prescribes you a new medication, tell them you're taking Pristiq XR (Desvenlafaxine). This is especially important before any procedure where Linezolid or methylene blue might be used.

Final Thoughts

Most people take Pristiq XR safely alongside other medications — but some combinations are dangerous. The biggest risks are serotonin syndrome (from combining with other serotonergic drugs or MAOIs) and increased bleeding (from NSAIDs or blood thinners).

When in doubt, ask your pharmacist or doctor. They can cross-check your full medication list for interactions.

For more about Pristiq XR, see our guides on side effects, how it works, and uses and dosage. Ready to fill your prescription? Medfinder can help you find a pharmacy with Pristiq XR in stock near you.