Phenylephrine and Tranylcypromine Interaction

Drug interaction information between Phenylephrine and Tranylcypromine.

Phenylephrine and Tranylcypromine have a documented major interaction in FDA labeling.

FDA drug labeling documents a major-severity interaction between Phenylephrine and Tranylcypromine. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Phenylephrine

Alpha-1 Agonist

Drug B

Tranylcypromine

Monoamine Oxidase Inhibitor (MAOI)

How They Interact

Tranylcypromine blocks the enzyme that normally processes phenylephrine, leading to an extreme and unsafe increase in blood pressure.

FDA Label Information

Excessive reduction of blood glucose (additive effect) [See Warnings and Precautions (5.14)] ; CNS depressant agents (including opioids, alcohol, sedatives, hypnotics) Use with caution Increased CNS depression Dietary supplements containing sympathomimetics Contraindicated Antidepressants including but not limited to: • Other MAOIs (e.g., linezolid, intravenous methylene blue, selective MAOIs) • Selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) • Tricyclic antidepressants • Amoxapine, bupropion, maprotiline, nefazodone, trazodone,...

Phenylephrine Also Interacts With

View all Phenylephrine interactions →

Frequently Asked Questions

What SPL severity band is on file for Phenylephrine + Tranylcypromine?

Compiled FDA labeling labels this pair major. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Tranylcypromine has 42 labeled pairs on file vs Phenylephrine's 2. In the major band specifically: Phenylephrine has 1; Tranylcypromine has 7 (also Bupropion, Linezolid, Vilazodone, Epinephrine).

What mechanism field is on file for Phenylephrine and Tranylcypromine?

Tranylcypromine blocks the enzyme that normally processes phenylephrine, leading to an extreme and unsafe increase in blood pressure.

Tranylcypromine carries more major-labeled pairs than Phenylephrine

SPL source-record counts only. This page's band is major · classes on file: Phenylephrine (Alpha-1 Agonist); Tranylcypromine (Monoamine Oxidase Inhibitor (MAOI)).

Tranylcypromine has 7 major-labeled pairs vs Phenylephrine's 1.

Phenylephrine

1 major · 0 moderate · 1 minor · 2 total

Phenylephrine has no other major-band peer in this dataset besides Tranylcypromine.

Tranylcypromine

7 major · 23 moderate · 12 minor · 42 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.