What the FDA labels say about taking them together
Fentanyl and linezolid
Fentanyl's FDA label of March 6, 2026 names linezolid in its drug interactions section; linezolid's label does not name fentanyl itself but warns about its class (Opioids (opioid agonists)). The fentanyl label: “The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome [see.”
Check it at the source: the fentanyl FDA label on DailyMed (effective March 6, 2026, Hikma Pharmaceuticals USA Inc.); the linezolid FDA label on DailyMed (effective June 19, 2026, Hospira, Inc.).
What does the fentanyl label say about linezolid?
Fentanyl label, drug interactionsSerotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome [see. … monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).
Fentanyl label, warnings and precautionsSerotonergic 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 muscle relaxants (i.e., cyclobenzaprine, metaxalone), and drugs that impair metabolism of serotonin (including MAO inhibitors, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue) [see Drug Interactions (7) ].
Source: FDA drug label (Fentanyl Citrate, NDA019115), Hospira, Inc., effective August 24, 2026 (SPL set bfa8018a-4cbc-434b-e09e-782872b0340a), via openFDA
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 linezolid label say about fentanyl?
Linezolid's label does not name fentanyl itself; it warns about its class (Opioids (opioid agonists)):
Linezolid label, warnings and precautionsSpontaneous reports of serotonin syndrome including fatal cases associated with the concomitant use of linezolid and serotonergic agents have been reported. Commonly used serotonergic agents include serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, buspirone, serotonin 5-HT1 receptor agonists (triptans), and opioids, including meperidine.
Linezolid label, warnings and precautionsSpontaneous reports of serotonin syndrome including fatal cases associated with the concomitant use of ZYVOX and serotonergic agents have been reported. Commonly used serotonergic agents include serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, buspirone, serotonin 5‑HT1 receptor agonists (triptans), and opioids, including meperidine.
Source: FDA drug label (Linezolid), Hospira, Inc., effective June 19, 2026 (SPL set c401f1a8-cc37-461b-bfef-f2e156629bf8), 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
| Fentanyl | Linezolid | |
|---|---|---|
| Labeled for | Pain | Bacterial infections |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $1.79 per mL 100 mcg/2 mL vial | $1.44 per tablet 600 mg tablet |
| Shortage now | In shortage | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once