Methylnaltrexone and Tapentadol interaction
Methylnaltrexone and Tapentadol: 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 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.
From the Tapentadol label · effective 2026-02-26
Management of respiratory depression may include close observation, supportive measures, and use of opioid antagonists, depending on the patient's clinical status [see Overdosage (10) ] .
Educate patients and caregivers on how to recognize respiratory depression and emphasize the importance of calling 911 or getting emergency medical help, even if naloxone is administered .
Due to the risk of respiratory depression with concomitant use of skeletal muscle relaxants and opioids, consider prescribing naloxone for the emergency treatment of opioid overdose [see Dosage and Administration (2.2) , Warnings and Precautions (5.2 , 5.3) ] Examples: cyclobenzaprine, metaxalone Diuretics Clinical Impact: Opioids can reduce the efficacy of diuretics…
Consider prescribing naloxone for the emergency treatment of opioid overdose [see Dosage and Administration (2.2) , Warnings and Precautions (5.2) ] .
Patient Access to Naloxone for the Emergency Treatment of Opioid Overdose Discuss the availability of naloxone for the emergency treatment of opioid overdose with the patient and caregiver and assess the potential need for access to naloxone, both when initiating and renewing treatment with tapentadol tablets.
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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.