Methadone and Naldemedine interaction
Methadone and Naldemedine: 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 Naldemedine (SYMPROIC) label · effective 2025-07-25
Intervention Avoid use of SYMPROIC with another opioid antagonist.
Other opioid antagonists : Potential for additive effect and increased risk of opioid withdrawal; avoid concomitant use ( 7 )
Opioid withdrawal : Consider the overall risk benefit in patients with disruptions to the blood-brain barrier.
Monitor symptoms of opioid withdrawal ( 5.2 )
Opioid Withdrawal Clusters of symptoms consistent with opioid withdrawal, including hyperhidrosis, chills, increased lacrimation, hot flush/flushing, pyrexia, sneezing, feeling cold, abdominal pain, diarrhea, nausea, and vomiting have occurred in patients treated with SYMPROIC [see Adverse Reactions (6.1) ] .
From the Methadone (METHADOSE) label · effective 2026-04-27
Patient Access to an Opioid Overdose Reversal Agent for the Emergency Treatment of Opioid Overdose 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.
Advise patients and caregivers that an opioid overdose reversal agent, such as naloxone or nalmefene, may also be administered for a known or suspected overdose with METHADOSE itself [see Overdosage ( 10 )] .
Examples: phenelzine, tranylcypromine, linezolid Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics Clinical Impact: Patients maintained on methadone may experience withdrawal symptoms when given opioid antagonists, mixed agonist/antagonists, and partial agonists.
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.