What the FDA labels say about taking them together
Epinephrine and levothyroxine
Epinephrine's FDA label of July 13, 2026 names levothyroxine in its drug interactions section; the levothyroxine labels PlainMeds reads (4) do not name epinephrine. The epinephrine label: “… antidepressants, MAO inhibitors, COMT inhibitors, clonidine, doxapram, oxytocin, levothyroxine sodium, and certain antihistamines. ( 7.2) Drugs that increase the arrhythmogenic potential of epinephrine include beta …”
Check it at the source: the epinephrine FDA label on DailyMed (effective July 13, 2026, A-S Medication Solutions); the levothyroxine FDA label on DailyMed (effective February 20, 2024, AbbVie Inc.).
What does the epinephrine label say about levothyroxine?
Epinephrine label, drug interactionsDRUG INTERACTIONS Drugs that counter the pressor effects of epinephrine include alpha blockers, vasodilators such as nitrates, diuretics, antihypertensives, and ergot alkaloids. ( 7 .1) Drugs that potentiate the effects of epinephrine include sympathomimetics, beta blockers, tricyclic antidepressants, MAO inhibitors, COMT inhibitors, clonidine, doxapram, oxytocin, levothyroxine sodium, and certain antihistamines. ( 7 .2) Drugs that increase the arrhythmogenic potential of epinephrine include beta blockers, cyclopropane and halogenated hydrocarbon anesthetics, quinidine, antihistamines, exogenous thyroid hormones, diuretics, and cardiac glycosides.
Epipen label (Viatris Specialty LLC, February 15, 2023), drug interactionsAntidepressants, Monoamine Oxidase Inhibitors, Levothyroxine, and Antihistamines The effects of epinephrine may be potentiated by tricyclic antidepressants, monoamine oxidase inhibitors, levothyroxine sodium, and certain antihistamines, notably chlorpheniramine, tripelennamine, and diphenhydramine.
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 (Epinephrine, NDA205029), BPI Labs, LLC, effective December 26, 2025 (SPL set db18519b-82a9-435b-85c7-a040d644f057), 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 levothyroxine label say about epinephrine?
Levothyroxine's label (effective February 20, 2024) and its 3 other brand-application labels do not name epinephrine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Synthroid), AbbVie Inc., effective February 20, 2024 (SPL set 1e11ad30-1041-4520-10b0-8f9d30d30fcc), 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 | Levothyroxine | |
|---|---|---|
| Labeled for | Asthma | Hypothyroidism |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $123.51 per unit 0.15 mg auto-injct | $0.0588 per tablet 112 mcg tablet |
| 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