Nalmefene and Naltrexone interaction
Nalmefene and Naltrexone: the Naltrexone prescribing label describes an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Naltrexone label · effective 2026-01-30
Strongly consider recommending or prescribing an opioid reversal agent (e.g., naloxone, nalmefene) for the emergency treatment of opioid overdose (5.1) .
…Overdose Reversal Agent for the Emergency Treatment of Opioid Overdose At the initial naltrexone for extended-release injectable suspension injection and with each subsequent injection, inform patients and caregivers about opioid overdose reversal agents (e.g., naloxone, nalmefene) and discuss the importance of having access to an opioid overdose reversal agent.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.