Levorphanol and Methadone interaction

Levorphanol and Methadone: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Levorphanol (Levorphanol Tartrate) label · effective 2026-04-28

Major

…LIFE-THREATENING RISKS FROM USE OF LEVORPHANOL TARTRATE TABLETS Addiction, Abuse, and Misuse Because the use of Levorphanol Tartrate Tablets exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death, assess each patient’s risk prior to prescribing and reassess all patients regularly for the development of…

Boxed warningby drug classView label on DailyMed
Major

Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death.

Boxed warningby drug classView label on DailyMed
Major

Reserve concomitant prescribing of Levorphanol Tartrate Tablets and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate ( see WARNINGS ).

Boxed warningby drug classView label on DailyMed
Major

Overestimating the Levorphanol Tartrate Tablets dosage when converting patients from another opioid product can result in a fatal overdose with the first dose.

Warningsby drug classView label on DailyMed
Major

Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Profound sedation, respiratory depression, coma, and death may result from the concomitant use of Levorphanol Tartrate Tablets with benzodiazepines and/or other CNS depressants, including alcohol [e.g., non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants,…

Warningsby drug classView label on DailyMed

From the Methadone (METHADOSE) label · effective 2026-04-27

Major

Managing Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, is a risk factor for respiratory depression and death [see Warnings and Precautions ( 5.2 )].

Boxed warningby drug classView label on DailyMed
Major

Reserve concomitant prescribing of benzodiazepines or other CNS depressants in patients in methadone treatment to those for whom alternatives to benzodiazepines or other CNS depressants are inadequate.

Boxed warningby drug classView label on DailyMed
Major

Concomitant use with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, and death.

Boxed warningby drug classView label on DailyMed
Major

To further reduce the risk of respiratory depression, consider the following: Patients tolerant to other opioids may be incompletely tolerant to methadone.

Warnings and precautionsby drug classView label on DailyMed
Major

Deaths have been reported during conversion from chronic, high-dose treatment with other opioid agonists.

Warnings and precautionsby drug classView label on DailyMed

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Not 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.