Isoproterenol and Promethazine and dextromethorphan interaction
Isoproterenol and Promethazine and dextromethorphan: 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 Promethazine and dextromethorphan (Promethazine Hydrochloride and Dextromethorphan Hydrobromide) label · effective 2025-08-08
Epinephrine – Because of the potential for promethazine to reverse epinephrine’s vasopressor effect, epinephrine should NOT be used to treat hypotension associated with Promethazine Hydrochloride and Dextromethorphan Hydrobromide Oral Solution overdose.
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.