What the FDA labels say about taking them together
Phenelzine and procarbazine
Phenelzine's FDA label of June 6, 2025 names procarbazine in its contraindications section; the procarbazine label PlainMeds reads does not name phenelzine.
Check it at the source: the phenelzine FDA label on DailyMed (effective June 6, 2025, Parke-Davis Div of Pfizer Inc); the procarbazine FDA label on DailyMed (effective September 16, 2024, Leadiant Biosciences, Inc.).
What does the phenelzine label say about procarbazine?
Phenelzine label, contraindicationsA List of MAO Inhibitors by Generic Name Follows: pargyline hydrochloride pargyline hydrochloride and methylclothiazide furazolidone isocarboxazid procarbazine tranylcypromine NARDIL should also not be used in combination with buspirone HCl, since several cases of elevated blood pressure have been reported in patients taking MAO inhibitors who were then given buspirone HCl.
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 procarbazine label say about phenelzine?
Procarbazine's label (effective September 16, 2024) does 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 (Matulane), Leadiant Biosciences, Inc., effective September 16, 2024 (SPL set 1aa75a3a-18c9-49e1-91a6-293d0b7da756), 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 | Procarbazine | |
|---|---|---|
| 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 | 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