Levomilnacipran XR Drug Interactions You Need to Know

When you take more than one medication, there's always a chance they'll interact with each other — sometimes in ways that reduce effectiveness, and sometimes in ways that are genuinely dangerous. Levomilnacipran XR (brand name Fetzima) has several important drug interactions you should understand before starting treatment.

This guide covers the major and moderate interactions, supplements and OTC medications to watch for, and what information your doctor needs from you.

How Drug Interactions Work

Drug interactions happen in a few different ways:

• Additive effects: Two drugs that do similar things can amplify each other's effects beyond what's safe. For example, taking two medications that both raise serotonin levels can push you into dangerous territory.
• Metabolic interference: Some drugs are broken down by the same liver enzymes. If one drug blocks those enzymes, the other drug builds up to higher-than-expected levels in your body.
• Opposing effects: Sometimes one medication directly counteracts another. For instance, Levomilnacipran XR's norepinephrine activity can raise blood pressure, which can work against blood pressure medications.

Levomilnacipran XR is primarily metabolized by the liver enzyme CYP3A4 and eliminated through the kidneys. This means drugs that strongly affect CYP3A4 can change how much Levomilnacipran XR ends up in your system.

Major Drug Interactions (Avoid These Combinations)

MAOIs (Monoamine Oxidase Inhibitors)

This is the most dangerous interaction. Combining Levomilnacipran XR with an MAOI can cause serotonin syndrome — a potentially life-threatening condition. MAOIs include:

• Phenelzine (Nardil)
• Tranylcypromine (Parnate)
• Isocarboxazid (Marplan)
• Selegiline (Emsam patch — at higher doses)
• Linezolid (Zyvox) — an antibiotic that also has MAOI activity
• Methylene blue (IV) — used in some medical procedures

The rule: Wait at least 14 days after stopping an MAOI before starting Levomilnacipran XR. Wait at least 7 days after stopping Levomilnacipran XR before starting an MAOI. No exceptions.

Other Serotonergic Medications

Taking Levomilnacipran XR with other drugs that increase serotonin raises the risk of serotonin syndrome. These include:

• Other SNRIs: Duloxetine (Cymbalta), Venlafaxine (Effexor XR), Desvenlafaxine (Pristiq)
• SSRIs: Sertraline (Zoloft), Fluoxetine (Prozac), Escitalopram (Lexapro), Paroxetine (Paxil), Citalopram (Celexa)
• Tricyclic antidepressants: Amitriptyline, Nortriptyline (Pamelor), Imipramine (Tofranil)
• Triptans (migraine medications): Sumatriptan (Imitrex), Rizatriptan (Maxalt), Zolmitriptan (Zomig)
• Opioids: Fentanyl, Tramadol (Ultram), Meperidine (Demerol) — these have serotonergic activity
• Buspirone (Buspar) — an anti-anxiety medication
• Lithium — a mood stabilizer
• Tryptophan supplements

This doesn't mean all combinations are absolutely forbidden — your doctor may carefully prescribe some of these together with close monitoring. But you need to know the risk.

Symptoms of serotonin syndrome include agitation, confusion, rapid heartbeat, high blood pressure, dilated pupils, muscle twitching, high fever, and loss of coordination. Seek emergency care immediately if you experience these symptoms.

Strong CYP3A4 Inhibitors

These medications slow down the liver enzyme that breaks down Levomilnacipran XR, causing it to build up in your body:

• Ketoconazole (antifungal)
• Clarithromycin (Biaxin — antibiotic)
• Itraconazole (Sporanox — antifungal)
• Ritonavir (Norvir — HIV medication)

If you must take a strong CYP3A4 inhibitor, your Levomilnacipran XR dose should not exceed 80 mg/day.

Moderate Drug Interactions (Use With Caution)

NSAIDs and Aspirin

Nonsteroidal anti-inflammatory drugs increase the risk of bleeding when combined with Levomilnacipran XR. This includes common OTC medications like:

• Ibuprofen (Advil, Motrin)
• Naproxen (Aleve)
• Aspirin
• Celecoxib (Celebrex)

Occasional use may be okay, but talk to your doctor before taking these regularly. If you need pain relief, acetaminophen (Tylenol) is generally a safer choice.

Blood Thinners (Anticoagulants)

SNRIs including Levomilnacipran XR can interfere with platelet function. Combined with blood thinners, this increases bleeding risk:

• Warfarin (Coumadin)
• Apixaban (Eliquis)
• Rivaroxaban (Xarelto)
• Heparin

If you take a blood thinner, your doctor should monitor you more closely for signs of unusual bleeding or bruising.

Blood Pressure Medications

Because Levomilnacipran XR can raise blood pressure through its norepinephrine activity, it can partially counteract antihypertensive medications. This doesn't mean you can't take both — but your doctor may need to adjust your blood pressure medication doses and monitor you more frequently.

CYP3A4 Inducers

These medications speed up the breakdown of Levomilnacipran XR, potentially making it less effective:

• Carbamazepine (Tegretol)
• Phenytoin (Dilantin)
• Rifampin (Rifadin)
• St. John's Wort (also a serotonin risk — double reason to avoid)

Supplements and OTC Products to Watch

Don't assume that "natural" means "safe to combine." Several common supplements interact with Levomilnacipran XR:

• St. John's Wort: Increases serotonin AND induces CYP3A4. This is a double-whammy — it raises serotonin syndrome risk while potentially reducing Levomilnacipran XR's effectiveness. Avoid this combination.
• Tryptophan / 5-HTP: These serotonin precursors can add to serotonin levels and increase the risk of serotonin syndrome.
• Fish oil (high-dose omega-3s): May increase bleeding risk at high doses when combined with Levomilnacipran XR. Moderate doses are likely fine, but mention it to your doctor.
• Ginkgo biloba: Can also increase bleeding risk.
• SAMe (S-adenosylmethionine): Has serotonergic activity and should be used cautiously.

Food and Drink Interactions

Levomilnacipran XR has no significant food interactions. You can take it with or without food.

However, there are a couple things to keep in mind:

• Alcohol: While there's no specific contraindication, alcohol can worsen depression and may amplify certain side effects like dizziness and impaired judgment. Use caution and moderation.
• Grapefruit: Grapefruit inhibits CYP3A4, which could theoretically increase Levomilnacipran XR levels. The effect is usually mild, but if you consume large amounts of grapefruit or grapefruit juice, mention it to your doctor.

What to Tell Your Doctor

Before starting Levomilnacipran XR, give your doctor a complete list of:

• All prescription medications — including those prescribed by other doctors
• Over-the-counter medications — pain relievers, allergy medications, cold medicines
• Supplements and vitamins — including herbal products and amino acids
• Recreational substances — including marijuana and alcohol use

Don't assume your doctor knows about something another provider prescribed. And don't skip mentioning supplements because you think they "don't count" — they absolutely do when it comes to drug interactions.

If you start any new medication while taking Levomilnacipran XR, check with your pharmacist or doctor before taking the first dose. Your pharmacist can run an interaction check in seconds.

Final Thoughts

Levomilnacipran XR has several important drug interactions, but most can be managed with proper communication and monitoring. The biggest risks are combining it with MAOIs or other serotonergic medications, and using it with strong CYP3A4 inhibitors without dose adjustment.

The single best thing you can do to stay safe: keep one up-to-date medication list and share it with every provider and pharmacist you see.

For more on Levomilnacipran XR, see our guides on what it is and how to take it and side effects to watch for.