What the FDA labels say about taking them together
Methadone and selegiline
Selegiline's FDA label (Zelapar) of June 1, 2021 names methadone in its contraindications section; methadone's label does not name selegiline itself but warns about its class (MAO inhibitors). The selegiline label: “CONTRAINDICATIONS ZELAPAR is contraindicated in patients with: Concomitant use of opioid drugs.”
Check it at the source: the methadone FDA label on DailyMed (effective December 8, 2025, Epic Pharma, LLC); the selegiline FDA label on DailyMed (effective August 7, 2024, Rising Pharma Holdings, Inc.).
What does the methadone label say about selegiline?
Methadone's label does not name selegiline 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 selegiline label say about methadone?
Zelapar label (Bausch Health US, LLC, June 1, 2021), contraindicationsCONTRAINDICATIONS ZELAPAR is contraindicated in patients with: Concomitant use of opioid drugs (e.g., meperidine, tramadol, or methadone).
Zelapar label (Bausch Health US, LLC, June 1, 2021), drug interactionsDRUG INTERACTIONS 7.1 Opioid Drugs Because serious, sometimes fatal reactions have been precipitated with concomitant use of opioid drugs (e.g., meperidine and its derivatives, methadone, or tramadol) and MAOIs, including selective MAO-B inhibitors, concomitant use of these drugs with ZELAPAR is contraindicated [see Contraindications ( 4 ) and Warnings and Precautions ( 5.2 )].
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
| Methadone | Selegiline | |
|---|---|---|
| Labeled for | Pain, Opioid use disorder | Parkinson's disease, Depression |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.177 per tablet 10 mg tablet | $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