What the FDA labels say about taking them together
Phenelzine and sufentanil
Sufentanil's FDA label of June 1, 2026 names phenelzine in its drug interactions section; the phenelzine label PlainMeds reads does not name sufentanil. The sufentanil label: “MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity.”
Check it at the source: the phenelzine FDA label on DailyMed (effective June 6, 2025, Parke-Davis Div of Pfizer Inc); the sufentanil FDA label on DailyMed (effective June 1, 2026, Hospira, Inc.).
What does the phenelzine label say about sufentanil?
Phenelzine's label (effective June 6, 2025) does not name sufentanil 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
What does the sufentanil label say about phenelzine?
Sufentanil label, drug interactionsMonoamine Oxidase Inhibitors (MAOIs) Clinical Impact: MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (…). Intervention: The use of Sufentanil Citrate Injection is not recommended for patients taking MAOIs or within 14 days of stopping such treatment. Examples: phenelzine, tranylcypromine, linezolid
Source: FDA drug label (Sufentanil Citrate), Hospira, Inc., effective June 1, 2026 (SPL set 20293943-46ff-4345-1aa4-929b4e017a25), 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
| Phenelzine | Sufentanil | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.586 per tablet 15 mg tablet | n/a |
| Shortage now | No current entry | In shortage |
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