Promethazine and dextromethorphan and Selegiline interaction
Promethazine and dextromethorphan and Selegiline: 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 Selegiline (ZELAPAR) label · effective 2021-06-01
• Concomitant use of dextromethorphan, because of reported episodes of psychosis or bizarre behavior.
ZELAPAR is contraindicated in patients using the following drugs: opioid drugs (e.g., meperidine, tramadol, methadone), MAO inhibitors including selective MAO-B inhibitors, dextromethorphan, St.
Therefore, in view of ZELAPAR’s MAO inhibitory activity, dextromethorphan should not be used concomitantly with ZELAPAR [see Contraindications (4) ] .
Dextromethorphan The combination of MAO inhibitors and dextromethorphan has been reported to cause brief episodes of psychosis or bizarre behavior.
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.