What the FDA labels say about taking them together
Nalbuphine and phenelzine
Nalbuphine's FDA label of December 31, 2025 names phenelzine in its drug interactions section; the phenelzine label PlainMeds reads does not name nalbuphine. The nalbuphine label: “Monoamine Oxidase Inhibitors (MAOIs) MAOI interactions with opioids may manifest as serotonin syndrome [see PRECAUTIONS;”
Check it at the source: the nalbuphine FDA label on DailyMed (effective December 31, 2025, Hospira, Inc.); the phenelzine FDA label on DailyMed (effective June 6, 2025, Parke-Davis Div of Pfizer Inc).
What does the nalbuphine label say about phenelzine?
Nalbuphine label, drug interactionsMonoamine Oxidase Inhibitors (MAOIs) MAOI (e.g., phenelzine, tranylcypromine, linezolid) interactions with opioids may manifest as serotonin syndrome [see PRECAUTIONS;
Source: FDA drug label (Nalbuphine Hydrochloride), Hospira, Inc., effective December 31, 2025 (SPL set 6025e8d4-5083-4c3a-58a0-050e7b0b6150), via openFDA; the full label on DailyMed
What does the phenelzine label say about nalbuphine?
Phenelzine's label (effective June 6, 2025) does not name nalbuphine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Nardil), Parke-Davis Div of Pfizer Inc, effective June 6, 2025 (SPL set 513a41d0-37d4-4355-8a6d-a2c643bce6fa), 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
| Nalbuphine | Phenelzine | |
|---|---|---|
| Labeled for | Pain | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $4.32 per mL 10 mg/mL ampul | $0.586 per tablet 15 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