What the FDA labels say about taking them together
Epinephrine and phentolamine
Epinephrine's FDA label of July 13, 2026 names phentolamine in its drug interactions section, and phentolamine's label names epinephrine too. The epinephrine label: “DRUG INTERACTIONS Drugs antagonizing pressor effects of epinephrine α-blockers, such as phentolamine Vasodilators, such as nitrates Diuretics Antihypertensives Ergot alkaloids Drugs potentiating pressor effects of …”
Check it at the source: the epinephrine FDA label on DailyMed (effective July 13, 2026, A-S Medication Solutions); the phentolamine FDA label on DailyMed (effective March 15, 2026, Oyster Point Pharma, Inc.).
What does the epinephrine label say about phentolamine?
Epinephrine label, drug interactionsα-blockers, such as phentolamine Vasodilators, such as nitrates
Epinephrine label, warnings and precautionsAntidote for Extravasation Ischemia: To prevent sloughing and necrosis in areas in which extravasation has taken place, infiltrate the area with 10 mL to 15 mL of saline solution containing from 5 mg to 10 mg of phentolamine, an adrenergic blocking agent.
Epipen label (Viatris Specialty LLC, February 15, 2023), drug interactionsAlpha-Adrenergic Blockers The vasoconstricting and hypertensive effects of epinephrine are antagonized by alpha- adrenergic blocking drugs, such as phentolamine.
Adrenalin (Epinephrine In Sodium Chloride) label (Par Health USA, LLC, August 1, 2023), drug interactionsDrugs Antagonizing Pressor Effects of Epinephrine α-blockers, such as phentolamine Vasodilators, such as nitrates Diuretics Antihypertensives Ergot alkaloids Phenothiazine antipsychotics 7.2.
Epinephrine label (BPI Labs, LLC, December 26, 2025), drug interactionsDRUG INTERACTIONS Drugs antagonizing pressor effects of epinephrine α-blockers, such as phentolamine Vasodilators, such as nitrates Diuretics Antihypertensives Ergot alkaloids Drugs potentiating pressor effects of epinephrine Sympathomimetics β-blockers, such as propranolol Tricyclic anti-depressants Monoamine oxidase (MAO) inhibitors Catechol-O-methyl transferase (COMT) inhibitors, such as entacapone Clonidine Doxapram Oxytocin Drugs potentiating arrhythmogenic effects of epinephrine Patients who are concomitantly receiving any of the following drugs should be observed carefully for the development of cardiac arrhythmias [see Warnings and Precautions (5.6) and Adverse Reactions (6) ]. …
Source: FDA drug label (Epipen, NDA019430), Viatris Specialty LLC, effective February 15, 2023 (SPL set 7560c201-9246-487c-a13b-6295db04274a), via openFDA
Source: FDA drug label (Adrenalin (Epinephrine In Sodium Chloride), NDA215875), Par Health USA, LLC, effective August 1, 2023 (SPL set 61b0e2a2-71ed-43d6-b1a7-36d2dae651b5), via openFDA
Source: FDA drug label (Epinephrine), A-S Medication Solutions, effective July 13, 2026 (SPL set 6e811e28-0199-4df7-a916-5940c632401d), via openFDA; the full label on DailyMed
What does the phentolamine label say about epinephrine?
Oraverse label (Septodont, Inc., December 5, 2018), drug interactionsLidocaine and Epinephrine When OraVerse was administered as an intraoral submucosal injection 30 minutes after injection of a local anesthetic, 2% lidocaine HCl with 1:100,000 epinephrine, the lidocaine concentration increased immediately after OraVerse intraoral injection.
Source: FDA drug label (Oraverse, NDA022159), Septodont, Inc., effective December 5, 2018 (SPL set 4025cf98-ea87-4531-b0fc-6283c84f63f3), via openFDA
Source: FDA drug label (Ryzumvi), NDA217064 (Famygen Life Sci), as published by Oyster Point Pharma, Inc., effective March 15, 2026 (SPL set 96bb1e53-c2cc-4e60-a21a-db0269c371bf), 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
| Epinephrine | Phentolamine | |
|---|---|---|
| Labeled for | Asthma | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $123.51 per unit 0.15 mg auto-injct | n/a |
| Shortage now | A presentation being discontinued | 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