What the FDA labels say about taking them together
Ondansetron and tramadol
Ondansetron's FDA label of January 8, 2026 names tramadol in its drug interactions section; the tramadol labels PlainMeds reads (3) do not name ondansetron. The ondansetron label: “Most reports have been associated with concomitant use of serotonergic drugs.”
Check it at the source: the ondansetron FDA label on DailyMed (effective January 8, 2026, Glenmark Pharmaceuticals Inc., USA); the tramadol FDA label on DailyMed (effective March 5, 2026, Lupin Pharmaceuticals, Inc.).
What does the ondansetron label say about tramadol?
Ondansetron label, drug interactionsAlthough no pharmacokinetic drug interaction between ondansetron and tramadol has been observed, data from 2 small trials indicate that when used together, ondansetron may increase patient-controlled administration of tramadol.
Ondansetron label, warnings and precautionsMost reports have been associated with concomitant use of serotonergic drugs (e.g., selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors, mirtazapine, fentanyl, lithium, tramadol, and intravenous methylene blue).
Source: FDA drug label (Ondansetron), Glenmark Pharmaceuticals Inc., USA, effective January 8, 2026 (SPL set eee5217a-eba8-463a-812d-bf3c66f0934f), via openFDA; the full label on DailyMed
What does the tramadol label say about ondansetron?
Tramadol's label (effective March 5, 2026) and its 2 other brand-application labels do not name ondansetron in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (TRAMADOL HYDROCHLORIDE), Lupin Pharmaceuticals, Inc., effective March 5, 2026 (SPL set 46bb9ae6-3ee8-463c-badb-c7a45a89b84b), 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
| Ondansetron | Tramadol | |
|---|---|---|
| Labeled for | Nausea and vomiting | Pain |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0582 per tablet 4 mg tablet | $0.0248 per tablet 50 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