What the FDA labels say about taking them together
Phenelzine and phentolamine
Phenelzine's FDA label of June 6, 2025 names phentolamine in its warnings section; the phentolamine labels PlainMeds reads (2) do not name phenelzine. The phenelzine label: “On the basis of present evidence, phentolamine is recommended. Care should be taken to administer this drug slowly in order to avoid producing an excessive hypotensive effect.”
Check it at the source: the phenelzine FDA label on DailyMed (effective June 6, 2025, Parke-Davis Div of Pfizer Inc); the phentolamine FDA label on DailyMed (effective March 15, 2026, Oyster Point Pharma, Inc.).
What does the phenelzine label say about phentolamine?
Phenelzine label, warningsOn the basis of present evidence, phentolamine is recommended. (The dosage reported for phentolamine is 5 mg intravenously.) Care should be taken to administer this drug slowly in order to avoid producing an excessive hypotensive effect.
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 phentolamine label say about phenelzine?
Phentolamine's label (effective March 15, 2026) and its 1 other brand-application label do not name phenelzine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Ryzumvi), NDA217064 (Famygen Life Sci), as published by Oyster Point Pharma, Inc., effective March 15, 2026 (SPL set 96bb1e53-c2cc-4e60-a21a-db0269c371bf), 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 | Phentolamine | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.586 per tablet 15 mg tablet | n/a |
| 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