Promethazine and dextromethorphan and Rasagiline interaction
Promethazine and dextromethorphan and Rasagiline: 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 Rasagiline label · effective 2020-06-30
Rasagiline is contraindicated for use with dextromethorphan because of risk of episode of psychosis or bizarre behavior.
Concomitant use of meperidine, tramadol, methadone, propoxyphene dextromethorphan, St.
Therefore, in view of rasagiline’s MAO inhibitory activity, dextromethorphan is contraindicated for use with rasagiline [see Contraindications ( 4 )] .
Dextromethorphan: Risk of psychosis or bizarre behavior ( 4 , 7.2 )
Dextromethorphan The concomitant use of rasagiline and dextromethorphan was not allowed in clinical studies.
From the Promethazine and dextromethorphan (Promethazine Hydrochloride and Dextromethorphan Hydrobromide) label · effective 2025-08-08
Dextromethorphan should not be used in patients receiving a monoamine oxidase inhibitor (see PRECAUTIONS – Drug Interactions ).
Drug Interactions Monoamine Oxidase (MAO) Inhibitors – Hyperpyrexia, hypotension, and death have been reported coincident with the co-administration of monoamine oxidase (MAO) inhibitors and products containing dextromethorphan.
Thus, concomitant administration of Promethazine Hydrochloride and Dextromethorphan Hydrobromide Oral Solution and MAO inhibitors should be avoided (see CONTRAINDICATIONS ).
Drug interactions, including an increased incidence of extrapyramidal effects, have been reported when some MAO inhibitors and phenothiazines are used concomitantly.
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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.