Methadone and Pentazocine and naloxone interaction
Methadone and Pentazocine and naloxone: 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 Methadone (METHADOSE) label · effective 2026-04-27
Withdrawal Avoid the use of mixed agonist/antagonist (i.e., pentazocine, nalbuphine, and butorphanol) or partial agonist (e.g., buprenorphine) analgesics in patients who are receiving a full opioid agonist, including METHADOSE.
Examples: butorphanol, nalbuphine, pentazocine, buprenorphine Muscle Relaxants Clinical Impact: Methadone may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression.
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 )].
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.
Concomitant use with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, and death.
From the Pentazocine and naloxone label · effective 2018-07-31
…MITIGATION STRATEGY (REMS); LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; NEONATAL OPIOID WITHDRAWAL SYNDROME; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS Addiction, Abuse, and Misuse Pentazocine and Naloxone Tablets exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to…
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 [ see Warnings and Precautions (5.X), Drug Interactions (7.X)] .
• Reserve concomitant prescribing of Pentazocine and Naloxone Tablets and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate.
Overestimating the Pentazocine and Naloxone Tablets dosage when converting patients from another opioid product can result in a fatal overdose with the first dose.
Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Profound sedation, respiratory depression, coma, and death may result from the concomitant use of Pentazocine and Naloxone Tablets with benzodiazepines or other CNS depressants (e.g., non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics,…
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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.