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What the FDA labels say about taking them together

Fentanyl and levomilnacipran

Levomilnacipran's FDA label of April 30, 2024 names fentanyl in its warnings and precautions section; fentanyl's label does not name levomilnacipran itself but warns about its class (SNRIs (serotonin and norepinephrine reuptake inhibitors)). The levomilnacipran label: “The risk is increased with concomitant use of other serotonergic drugs and with drugs that impair metabolism of serotonin, i.e., MAOIs.”

Check it at the source: the fentanyl FDA label on DailyMed (effective March 6, 2026, Hikma Pharmaceuticals USA Inc.); the levomilnacipran FDA label on DailyMed (effective April 30, 2024, Allergan, Inc.).

What does the fentanyl label say about levomilnacipran?

Fentanyl's label does not name levomilnacipran itself; it warns about its class (SNRIs (serotonin and norepinephrine reuptake inhibitors)):

Fentanyl label, warnings and precautions

If ‎a patient is suspected to be experiencing OIH, carefully consider appropriately ‎decreasing the dose of the current opioid analgesic or opioid rotation (safely ‎switching the patient to a different opioid moiety) [see Dosage and ‎Administration (2), Warnings and Precautions (5.7) ] .‎ 5.8 Serotonin Syndrome with Concomitant Use of Serotonergic Drugs Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of fentanyl with serotonergic drugs. …

Fentanyl label, warnings and precautions

Syndrome with Concomitant Use of Serotonergic Drugs Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of fentanyl with serotonergic drugs. Serotonergic drugs include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonergic neurotransmitter system (e.g., mirtazapine, trazadone, tramadol), certain …

Source: FDA drug label (Fentanyl Citrate), Hikma Pharmaceuticals USA Inc., effective March 6, 2026 (SPL set ce5db1c2-feb1-4ad2-847a-d02e865bd47e), via openFDA; the full label on DailyMed

What does the levomilnacipran label say about fentanyl?

Levomilnacipran label, warnings and precautions

The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St. John’s Wort) and with drugs that impair metabolism of serotonin, i.e., MAOIs [see Contraindications ( 4 ), Drug Interactions ( 7.1 )].

Source: FDA drug label (Fetzima), NDA204168 (Abbvie), as published by Allergan, Inc., effective April 30, 2024 (SPL set f371258d-91b3-4b6a-ac99-434a1964c3af), via openFDA; the full label on DailyMed

These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.

Both medicines on the record

6Fentanyl generic labelers
0Levomilnacipran generic labelers
FentanylLevomilnacipran
Labeled forPainDepression
Boxed warningYesYes
Pharmacy cost (NADAC)$1.79 per mL 100 mcg/2 mL vial$17.61 per unit 20-40 mg titration pak
Shortage nowIn shortageNo current entry

Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)

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