Nalmefene and Pentazocine and naloxone interaction
Nalmefene and Pentazocine and naloxone: the Nalmefene prescribing label flags 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 Nalmefene (Zurnai) label · effective 2026-07-31
Risk of Limited Efficacy with Partial Agonists or Mixed Agonists/Antagonists : Reversal of respiratory depression by partial agonists or mixed agonist/antagonists such as buprenorphine and pentazocine, may be incomplete.
Risk of Limited Efficacy with Partial Agonists or Mixed Agonist/Antagonists Reversal of respiratory depression by partial agonists or mixed agonist/antagonists such as buprenorphine and pentazocine, may be incomplete.
Risk of Recurrent Respiratory and CNS Depression : A recurrence of respiratory depression is possible, therefore, keep the patient under continued surveillance and administer repeat doses of ZURNAI using a new auto-injector with each dose while awaiting emergency medical assistance.
In neonates, opioid withdrawal may be life-threatening if not recognized and properly treated.
While the duration of action of nalmefene is as long as most opioids, a recurrence of respiratory depression is possible, even after an apparently adequate initial response to ZURNAI treatment [see Clinical Pharmacology (12.3) ].
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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.