What the FDA labels say about taking them together
Codeine and linezolid
Codeine's FDA label of December 22, 2025 names linezolid in its drug interactions section; linezolid's label does not name codeine itself but warns about its class (Opioids (opioid agonists)). The codeine label: “The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.”
Check it at the source: the codeine FDA label on DailyMed (effective December 22, 2025, Hikma Pharmaceuticals USA Inc.); the linezolid FDA label on DailyMed (effective June 19, 2026, Hospira, Inc.).
What does the codeine label say about linezolid?
Codeine 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. … monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).
Source: FDA drug label (Codeine sulfate), Hikma Pharmaceuticals USA Inc., effective December 22, 2025 (SPL set 010905f9-3bcb-4b50-9fe8-a3ad0010f14c), via openFDA; the full label on DailyMed
What does the linezolid label say about codeine?
Linezolid's label does not name codeine 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
| Codeine | Linezolid | |
|---|---|---|
| Labeled for | Pain | Bacterial infections |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.726 per tablet 30 mg tablet | $1.44 per tablet 600 mg tablet |
| Shortage now | No current entry | 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