Isoproterenol and Levothyroxine and liothyronine interaction
Isoproterenol and Levothyroxine and liothyronine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Levothyroxine and liothyronine (NP Thyroid 60) label · effective 2026-01-01
Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects.
From the Isoproterenol (Isoproterenol hydrochloride) label · effective 2026-03-17
Drugs that may potentiate clinical response of Isoproterenol Clinical Impact The effects of isoproterenol may be potentiated by tricyclic antidepressants, monoamine oxidase inhibitors, levothyroxine sodium, and certain antihistamines, notably chlorpheniramine, tripelennamine, and diphenhydramine.
Intervention Monitor hemodynamic parameters in patients who concurrently are taking tricyclic antidepressants, monoamine oxidase inhibitors, levothyroxine sodium and certain antihistamines.
• Concomitant use of tricyclic antidepressants, monoamine oxidase inhibitors, levothyroxine sodium and certain antihistamines; hemodynamic parameters may potentiate a clinical response of isoproterenol ( 7 )
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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.