What the FDA labels say about taking them together
Phenelzine and selegiline
Selegiline's FDA label of August 7, 2024 names phenelzine in its warnings section; phenelzine's label does not name selegiline itself but warns about its class (MAO inhibitors). The selegiline label: “Serotonin syndrome and hyperpyrexia have been reported with the combined treatment of an antidepressant and a non-selective MAOI or selective MAO-B inhibitors, such as selegiline (ELDEPRYL), rasagiline (AZILECT), and …”
Check it at the source: the phenelzine FDA label on DailyMed (effective June 6, 2025, Parke-Davis Div of Pfizer Inc); the selegiline FDA label on DailyMed (effective August 7, 2024, Rising Pharma Holdings, Inc.).
What does the phenelzine label say about selegiline?
Phenelzine's label does not name selegiline 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 selegiline label say about phenelzine?
Selegiline label, warningsSevere CNS toxicity associated with hyperpyrexia and death have been reported with the combination of tricyclic antidepressants and non-selective MAOIs (Phenelzine, Tranylcypromine).
Zelapar label (Bausch Health US, LLC, June 1, 2021), warnings and precautionsSerotonin syndrome and hyperpyrexia have been reported with the combined treatment of an antidepressant (e.g., selective serotonin reuptake inhibitors-SSRIs, serotonin-norepinephrine reuptake inhibitors-SNRIs, tricyclic antidepressants, tetracyclic antidepressants, triazolopyridine antidepressants) and a non-selective MAOI (e.g., phenelzine, tranylcypromine) or selective MAO-B inhibitors, such as selegiline (ELDEPRYL), rasagiline (AZILECT), and olanzapine (Zydis) selegiline (ZELAPAR).
Source: FDA drug label (Zelapar, NDA021479), Bausch Health US, LLC, effective June 1, 2021 (SPL set 380d7717-2a79-42f3-a712-efe5e7696ba0), via openFDA
Source: FDA drug label (Selegiline Hydrochloride), Rising Pharma Holdings, Inc., effective August 7, 2024 (SPL set 23c4481f-d150-40c6-addb-b3e454ca914f), 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 | Selegiline | |
|---|---|---|
| Labeled for | n/a | Parkinson's disease, Depression |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.586 per tablet 15 mg tablet | $0.756 per capsule 5 mg capsule |
| 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