What the FDA labels say about taking them together
Phenylephrine and tranylcypromine
Tranylcypromine's FDA label of July 2, 2025 names phenylephrine in its boxed warning section; phenylephrine's label does not name tranylcypromine itself but warns about its class (MAO inhibitors). The tranylcypromine label: “… raise blood pressure (sympathomimetic medicine), such as pseudoephedrine, phenylephrine and ephedrine.”
Check it at the source: the phenylephrine FDA label on DailyMed (effective August 19, 2026, Hikma Pharmaceuticals USA Inc.); the tranylcypromine FDA label on DailyMed (effective July 2, 2025, Advanz Pharma (US) Corp.).
What does the phenylephrine label say about tranylcypromine?
Phenylephrine's label does not name tranylcypromine itself; it warns about its class (MAO inhibitors):
Phenylephrine label, drug interactionsThe pressor effect of phenylephrine hydrochloride is increased in patients receiving: Monoamine oxidase inhibitors (MAOI), such as selegiline. β-adrenergic blockers α-2 adrenergic agonists, such as clonidine Steroids Tricyclic antidepressants Norepinephrine transport inhibitors, such as atomoxetine Ergot alkaloids, such as methylergonovine maleate Centrally-acting sympatholytic agents, such as guanfacine or reserpine Atropine sulfate
Phenylephrine label, drug interactionsDRUG INTERACTIONS Agonistic Effects (increase in BIORPHEN blood pressure effect) can occur with monoamine oxidase inhibitors (MAOI), oxytocin and oxytocic drugs, tricyclic antidepressants, angiotensin and aldosterone, atropine, steroids, norepinephrine transporter inhibitors, ergot alkaloids. ( 7.1 ) Antagonistic Effects (decrease in BIORPHEN blood pressure effect) can occur with α-adrenergic antagonists, phosphodiesterase Type 5 inhibitors, mixed α- and β-receptor antagonists, calcium channel blockers …
Source: FDA drug label (Phenylephrine Hydrochloride), Hikma Pharmaceuticals USA Inc., effective August 19, 2026 (SPL set e1a7ab4b-0afe-4463-a039-5be0323cf2f7), via openFDA; the full label on DailyMed
What does the tranylcypromine label say about phenylephrine?
Tranylcypromine label, boxed warningSee, "What is the most important information I should know about PARNATE?” and “What are the possible side effects of PARNATE?” Do not take PARNATE if you: take certain medicines, including: antidepressants, such as: other monoamine oxidase inhibitors (MAOIs) selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) tricyclic antidepressants other antidepressants, such as amoxapine, bupropion, maprotiline, nefazodone, trazodone, vilazodone, vortioxetine amphetamines and methylphenidates medicines that can raise blood pressure (sympathomimetic medicine), such as pseudoephedrine, phenylephrine and ephedrine.
Tranylcypromine label, contraindicationsOther monoamine oxidase inhibitors (MAOIs) Selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) Tricyclic antidepressants Other antidepressants (e.g., amoxapine, bupropion, maprotiline, nefazodone, trazodone, vilazodone, vortioxetine) Amphetamines and methylphenidates and derivatives Sympathomimetic products (e.g., cold, hay fever or weight reducing products that contain vasoconstrictors such as pseudoephedrine, phenylephrine, and ephedrine; …
Tranylcypromine label, drug interactions… Contraindicated a SS * Some drugs in these groups may also be listed in Table 4 below. ** Sympathomimetic drugs include amphetamines as well as cold, hay fever or weight-reducing products that contain vasoconstrictors such as pseudoephedrine, phenylephrine, and ephedrine) a [See Contraindications (4.1)]; b [See Warnings and Precautions (5.2)]; c [See Warnings and Precautions (5.3)] d If not otherwise specified in this table, consider avoiding concomitant use (see also information on medication-free intervals, use agent at the lowest appropriate dosage, monitor for effects of the interaction, advise the patient to report potential effects). e [See Warnings and Precautions (5.5)]; …
Source: FDA drug label (PARNATE), Advanz Pharma (US) Corp., effective July 2, 2025 (SPL set b72d8187-dfcc-4ea0-b5e9-c0be95b69a27), 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
| Phenylephrine | Tranylcypromine | |
|---|---|---|
| Labeled for | Cough and cold, Allergies | Depression |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $5.24 per mL 10% eye drop | $0.591 per tablet 10 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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