Meperidine and Methylene blue interaction
Meperidine and Methylene blue: 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 Methylene blue (PROVAYBLUE) label · effective 2025-05-28
WARNING: SEROTONIN SYNDROME WITH CONCOMITANT USE OF SEROTONERGIC DRUGS AND OPIOIDS PROVAYBLUE may cause serious or fatal serotonergic syndrome when used in combination with serotonergic drugs and opioids.
Avoid concomitant use of PROVAYBLUE with selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs) and opioids. [see Warnings and Precautions ( 5.1 ) and Drug Interactions ( 7.1 )].
WARNING: SEROTONIN SYNDROME WITH CONCOMITANT USE OF SEROTONERGIC DRUGS AND OPIOIDS See full prescribing information for complete boxed warning.
PROVAYBLUE may cause serious or fatal serotonergic syndrome when used in combination with serotonergic drugs and opioids.
Serotonin Syndrome with Concomitant Use of Serotonergic Drugs and Opioids The development of serotonin syndrome has been reported with the use of methylene blue class products.
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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.