What the FDA labels say about taking them together
Cocaine and phenelzine
Phenelzine's FDA label of June 6, 2025 names cocaine in its contraindications section; cocaine's label does not name phenelzine itself but warns about its class (MAO inhibitors).
Check it at the source: the cocaine FDA label on DailyMed (effective January 12, 2026, OMNIVIUM PHARMACEUTICALS LLC.); the phenelzine FDA label on DailyMed (effective June 6, 2025, Parke-Davis Div of Pfizer Inc).
What does the cocaine label say about phenelzine?
Cocaine's label does not name phenelzine itself; it warns about its class (MAO inhibitors):
Cocaine label, drug interactionsPlasma cholinesterase activity may be decreased by chronic administration of certain monoamine oxidase inhibitors, oral contraceptives, glucocorticoids, antimyasthenics (neostigmine), cyclophosphamide, and possibly thiotepa.
Cocaine label, drug interactionsCocaine hydrochloride may potentiate the effects and toxicity of MAO inhibitors.
Source: FDA drug label (NUMBRINO), OMNIVIUM PHARMACEUTICALS LLC., effective January 12, 2026 (SPL set d724b5b4-6654-4bf5-9eed-e2c7943084ed), via openFDA; the full label on DailyMed
What does the phenelzine label say about cocaine?
Phenelzine label, contraindicationsTherefore, patients being treated with NARDIL should not take sympathomimetic drugs (including amphetamines, cocaine, methylphenidate, dopamine, epinephrine, and norepinephrine) or related compounds (including methyldopa, L-dopa, L-tryptophan, L-tyrosine, and phenylalanine).
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
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
| Cocaine | Phenelzine | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | $0.586 per tablet 15 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