What the FDA labels say about taking them together
Phenelzine and rasagiline
Rasagiline's FDA label of June 30, 2020 names phenelzine in its warnings and precautions section; phenelzine's label does not name rasagiline itself but warns about its class (MAO inhibitors). The rasagiline label: “Serotonin syndrome has been reported with concomitant use of an antidepressant and a nonselective MAOI or selective MAO-B inhibitors, such as selegiline (Eldepryl) and rasagiline.”
Check it at the source: the phenelzine FDA label on DailyMed (effective June 6, 2025, Parke-Davis Div of Pfizer Inc); the rasagiline FDA label on DailyMed (effective June 30, 2020, Teva Pharmaceuticals USA, Inc.).
What does the phenelzine label say about rasagiline?
Phenelzine's label does not name rasagiline itself; it warns about its class (MAO inhibitors):
Phenelzine label, contraindicationsExcitation, seizures, delirium, hyperpyrexia, circulatory collapse, coma, and death have been reported in patients receiving MAOI therapy who have been given a single dose of meperidine.
Phenelzine label, contraindicationsThere have been reports of serious reactions (including hyperthermia, rigidity, myoclonic movements and death) when serotoninergic drugs (e.g., dexfenfluramine, fluoxetine, fluvoxamine, paroxetine, sertraline, citalopram, venlafaxine) have been combined with an MAO inhibitor.
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 rasagiline label say about phenelzine?
Rasagiline label, warnings and precautionsSerotonin syndrome has been reported with concomitant use of an antidepressant (e.g., selective serotonin reuptake inhibitors-SSRIs, serotonin-norepinephrine reuptake inhibitors-SNRIs, tricyclic antidepressants, tetracyclic antidepressants, triazolopyridine antidepressants) and a nonselective MAOI (e.g., phenelzine, tranylcypromine) or selective MAO-B inhibitors, such as selegiline (Eldepryl) and rasagiline.
Source: FDA drug label (Rasagiline), Teva Pharmaceuticals USA, Inc., effective June 30, 2020 (SPL set e802c83c-e581-4a11-b83d-1df47120078d), 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 | Rasagiline | |
|---|---|---|
| Labeled for | n/a | Parkinson's disease |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.586 per tablet 15 mg tablet | $0.521 per tablet 0.5 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