What the FDA labels say about taking them together
Methadone and rasagiline
Rasagiline's FDA label of June 30, 2020 names methadone in its contraindications section; methadone's label does not name rasagiline itself but warns about its class (MAO inhibitors). The rasagiline label: “Serotonin syndrome has also been reported with concomitant use of rasagiline with meperidine, tramadol, methadone, or propoxyphene.”
Check it at the source: the methadone FDA label on DailyMed (effective December 8, 2025, Epic Pharma, LLC); the rasagiline FDA label on DailyMed (effective June 30, 2020, Teva Pharmaceuticals USA, Inc.).
What does the methadone label say about rasagiline?
Methadone's label does not name rasagiline itself; it warns about its class (MAO inhibitors):
Methadone label, drug interactionsMAOI interactions with opioids may manifest as serotonin syndrome [see Warnings and Precautions (5.9) ] or opioid toxicity (e.g., respiratory depression, coma) [see Warnings and Precautions (5.3) ].
Methadone label, warnings and precautionsSyndrome with Concomitant Use of Serotonergic Drugs Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of methadone hydrochloride tablets 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 …
Source: FDA drug label (Methadone Hydrochloride), Epic Pharma, LLC, effective December 8, 2025 (SPL set 6da7501b-b881-4bc7-891a-74214a00a3ac), via openFDA; the full label on DailyMed
What does the rasagiline label say about methadone?
Rasagiline label, contraindicationsCONTRAINDICATIONS Rasagiline is contraindicated for use with meperidine, tramadol, methadone, propoxyphene, and MAO inhibitors (MAOIs), including other selective MAO-B inhibitors, because of risk of serotonin syndrome [see Warnings and Precautions ( 5.2 )].
Rasagiline label, warnings and precautionsSerotonin syndrome has also been reported with concomitant use of rasagiline with meperidine, tramadol, methadone, or propoxyphene.
Source: FDA drug label (Rasagiline), Teva Pharmaceuticals USA, Inc., effective June 30, 2020 (SPL set e802c83c-e581-4a11-b83d-1df47120078d), 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
| Methadone | Rasagiline | |
|---|---|---|
| Labeled for | Pain, Opioid use disorder | Parkinson's disease |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.177 per tablet 10 mg tablet | $0.521 per tablet 0.5 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