PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

Levomilnacipran and Phenelzine Interaction

Drug interaction information between Levomilnacipran and Phenelzine.

Levomilnacipran and Phenelzine have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Levomilnacipran and Phenelzine. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.

Drug A

Levomilnacipran

Serotonin-Norepinephrine Reuptake Inhibitor (SNRI)

Drug B

Phenelzine

Monoamine Oxidase Inhibitor (MAOI)

How They Interact

Both drugs increase serotonin levels in the brain, which can lead to a dangerous buildup called serotonin syndrome.

What To Do

Do not take these medicines together because the combination can cause serious side effects.

FDA Label Information

Examples: selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid, methylene blue Other Serotonergic Drugs Clinical Impact: Concomitant use of FETZIMA with other serotonergic drugs increases the risk of serotonin syndrome.

Levomilnacipran Also Interacts With

View all Levomilnacipran interactions →

Phenelzine Also Interacts With

View all Phenelzine interactions →

Frequently Asked Questions

Can I take Levomilnacipran and Phenelzine together?

This is a moderate interaction. Do not take these medicines together because the combination can cause serious side effects.

How serious is the interaction between Levomilnacipran and Phenelzine?

This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.

Why do Levomilnacipran and Phenelzine interact?

Both drugs increase serotonin levels in the brain, which can lead to a dangerous buildup called serotonin syndrome.

Understanding the Levomilnacipran and Phenelzine Interaction

FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Levomilnacipran belongs to the Serotonin-Norepinephrine Reuptake Inhibitor (SNRI) class and Phenelzine belongs to the Monoamine Oxidase Inhibitor (MAOI) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Both drugs increase serotonin levels in the brain, which can lead to a dangerous buildup called serotonin syndrome. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.

Context around a specific patient determines real-world impact. Levomilnacipran has 11 total documented interactions on file in this dataset, and Phenelzine has 27. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Do not take these medicines together because the combination can cause serious side effects. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.

An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Levomilnacipran or Phenelzine based on a web page, speak with your prescriber or pharmacist before making any change.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.