Epinephrine and Levothyroxine interaction
Epinephrine and Levothyroxine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Epinephrine label · effective 2026-07-06
• 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.
…[see Warnings and Precautions (5.6) and Adverse Reactions (6) ]. β-blockers, such as propranolol Cyclopropane or halogenated hydrocarbon anesthetics, such as halothane Antihistamines Thyroid hormones Diuretics Cardiac glycosides, such as digitalis glycosides Quinidine Drugs potentiating hypokalemic effects of epinephrine • Potassium depleting diuretics • Corticosteroids…
• 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.
• β-blockers, such as propranolol • Cyclopropane or halogenated hydrocarbon anesthetics, such as halothane • Antihistamines • Thyroid hormones • Diuretics • Cardiac glycosides, such as digitalis glycosides • Quinidine Drugs potentiating arrhythmogenic effects of epinephrine.
From the Levothyroxine (Levothyroxine Sodium) label · effective 2024-07-10
Sympathomimetics Concurrent use may of sympathomimetics and levothyroxine may increase the effects of sympathomimetics or thyroid hormone.
Thyroid hormones may increase the risk of coronary insufficiency when sympathomimetic agents are administered to patients with coronary artery disease.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.