Buprenorphine and naloxone and Methylnaltrexone interaction
Buprenorphine and naloxone and Methylnaltrexone: 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 Buprenorphine and naloxone label · effective 2026-06-16
Buprenorphine and naloxone sublingual tablet is contraindicated in patients with a history of hypersensitivity to buprenorphine or naloxone as serious adverse reactions, including anaphylactic shock, have been reported [see Warnings and Precautions (5.9) ] .
Hypersensitivity to buprenorphine or naloxone.
Use in Patients with Impaired Hepatic Function Buprenorphine/naloxone products are not recommended in patients with severe hepatic impairment and may not be appropriate for patients with moderate hepatic impairment.
However, buprenorphine/naloxone products are not recommended for initiation of treatment (induction) in patients with moderate hepatic impairment due to the increased risk of precipitated withdrawal.
If a CYP3A4 inducer is discontinued, consider buprenorphine and naloxone sublingual tablet dosage reduction and monitor for signs of respiratory depression.
From the Methylnaltrexone (Relistor) label · effective 2024-05-01
• Other Opioid Antagonists : Potential for additive effect and increased risk of opioid withdrawal; avoid concomitant use.
Other Opioid Antagonists Avoid concomitant use of RELISTOR with other opioid antagonists because of the potential for additive effects of opioid receptor antagonism and increased risk of opioid withdrawal.
• Opioid Withdrawal : Consider the overall risk benefit in patients with disruptions to the blood-brain barrier.
Monitor closely for symptoms of opioid withdrawal.
Patients having disruptions to the blood-brain barrier may be at increased risk for opioid withdrawal and/or reduced analgesia.
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.