What the FDA labels say about taking them together
Dextromethorphan and selegiline
Selegiline's FDA label (Zelapar) of June 1, 2021 names dextromethorphan in its contraindications section; dextromethorphan's label does not name selegiline itself but warns about its class (MAO inhibitors). The selegiline label: “… tramadol, methadone, pentazocine, and propoxyphene; and the antitussive agent dextromethorphan because of a risk of serotonin syndrome when EMSAM is used with these agents.”
Check it at the source: the dextromethorphan FDA label on DailyMed (effective August 27, 2026); the selegiline FDA label on DailyMed (effective August 7, 2024, Rising Pharma Holdings, Inc.).
What does the dextromethorphan label say about selegiline?
Dextromethorphan's label does not name selegiline itself; it warns about its class (MAO inhibitors):
Dextromethorphan label, warningsWarnings Do not use if you are now taking a prescription monoamine oxidase inhibitor (MAOI) (certain drugs for depression, psychiatric or emotional conditions, or Parkinson’s disease), or for 2 weeks after stopping the MAOI drug.
Dextromethorphan label, warningsIf you do not know if your prescription drug contains an MAOI, ask a doctor or pharmacist before taking this product.
Source: FDA drug label (Good Sense Cough DM), L. Perrigo Company, effective August 27, 2026 (SPL set 5a2e9bef-42cb-4b72-9a26-c3ae71dcb4ea), via openFDA; the full label on DailyMed
What does the selegiline label say about dextromethorphan?
Zelapar label (Bausch Health US, LLC, June 1, 2021), contraindicationsZELAPAR is contraindicated in patients using the following drugs: opioid drugs (e.g., meperidine, tramadol, methadone), MAO inhibitors including selective MAO-B inhibitors, dextromethorphan, St. John’s wort, and cyclobenzaprine
Zelapar label (Bausch Health US, LLC, June 1, 2021), drug interactionsThe combination of MAO inhibitors and dextromethorphan has been reported to cause brief episodes of psychosis or bizarre behavior.
Emsam label (Viatris Specialty LLC, May 15, 2020), contraindicationsEMSAM (selegiline transdermal system) is contraindicated with selective serotonin reuptake inhibitors (SSRIs, e.g., fluoxetine, sertraline, and paroxetine); serotonin and norepinephrine reuptake inhibitors (SNRIs, e.g., venlafaxine and duloxetine); the tricyclic antidepressants clomipramine and imipramine, the opiate analgesics meperidine, tramadol, methadone, pentazocine, and propoxyphene; and the antitussive agent dextromethorphan because of a risk of serotonin syndrome when EMSAM is used with these agents [see Warnings and Precautions (5.2) and Drug Interactions (7.1) ].
Source: FDA drug label (Zelapar, NDA021479), Bausch Health US, LLC, effective June 1, 2021 (SPL set 380d7717-2a79-42f3-a712-efe5e7696ba0), via openFDA
Source: FDA drug label (Emsam, NDA021336), Viatris Specialty LLC, effective May 15, 2020 (SPL set b891bd9f-fdb8-4862-89c5-ecdd700398a3), via openFDA
Source: FDA drug label (Selegiline Hydrochloride), Rising Pharma Holdings, Inc., effective August 7, 2024 (SPL set 23c4481f-d150-40c6-addb-b3e454ca914f), 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
| Dextromethorphan | Selegiline | |
|---|---|---|
| Labeled for | Cough and cold | Parkinson's disease, Depression |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.122 per unit 15 mg softgel | $0.756 per capsule 5 mg capsule |
| 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