Meperidine and Phenelzine interaction
Meperidine and Phenelzine: 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 Meperidine (DEMEROL) label · effective 2026-07-20
Concomitant Use of DEMEROL Injection with Monoamine Oxidase (MAO) Inhibitors Concomitant use of DEMEROL Injection with monoamine oxidase (MAO) inhibitors can result in coma, severe respiratory depression, cyanosis, and hypotension.
Use of DEMEROL Injection with MAO inhibitors within last 14 days is contraindicated [see Contraindications (4) , Warnings and Precautions (5.6) , Drug Interactions (7) ] .
• Concomitant use of DEMEROL Injection with Monoamine oxidase (MAO) inhibitors can result in coma, severe respiratory depression, cyanosis and hypotension.
Use of DEMEROL Injection with MAO inhibitors is contraindicated.
…Precautions (5.2) ] • Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see Warnings and Precautions (5.9) ] • Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days [see Warnings and Precautions (5.6) , Drug Interactions (7) ] • Known or suspected gastrointestinal obstruction,…
From the Phenelzine (phenelzine sulfate) label · effective 2026-05-21
Excitation, seizures, delirium, hyperpyrexia, circulatory collapse, coma, and death have been reported in patients receiving MAOI therapy who have been given a single dose of meperidine.
Concomitant use with meperidine is contraindicated (see WARNINGS ).
Phenelzine sulfate should not be used in combination with dextromethorphan or with CNS depressants such as alcohol and certain narcotics.
Patients should be warned that the use of the above foods, beverages, or medications may cause a reaction characterized by headache and other serious symptoms due to a rise in blood pressure, with the exception of dextromethorphan which may cause reactions similar to those seen with meperidine.
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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.