Holding Relistor Prior to Surgery
Hold Relistor (methylnaltrexone) on the morning of surgery and discontinue it entirely if the patient's opioid pain medication is being discontinued perioperatively.
Key Management Principles
The FDA label for Relistor explicitly states that the medication should be discontinued if treatment with opioid pain medication is also discontinued 1. This is the primary guiding principle for perioperative management.
Preoperative Discontinuation
- Hold on the morning of surgery: Do not administer Relistor on the day of the procedure 1
- Rationale: Relistor is a peripherally acting mu-opioid receptor antagonist that typically does not interfere with the analgesic properties of mu agonists (unless there is disruption of the blood-brain barrier) 2
- Critical distinction: Unlike naltrexone (which requires 3-4 days for oral formulations or 24-30 days for intramuscular formulations) 2, Relistor does not require an extended washout period before surgery
Important Perioperative Considerations
Relistor belongs to the peripherally acting mu-opioid receptor antagonist class, which behaves differently from centrally acting opioid antagonists like naltrexone. The 2021 SPAQI consensus guidelines recommend holding peripherally acting antagonists like alvimopan (Entereg) on the morning of surgery 2, and this same principle applies to Relistor.
The key distinction is that peripherally acting antagonists do not block central opioid analgesia in patients with an intact blood-brain barrier, so they pose less risk to postoperative pain control compared to naltrexone 2.
When to Restart Relistor
- Restart only after opioid therapy is resumed postoperatively 1
- Re-evaluate the continued need when the opioid regimen changes to avoid adverse reactions 1
- Ensure patient has close proximity to toilet facilities when restarting, as bowel movement typically occurs within 30-60 minutes of administration 1
Special Populations
For patients with chronic non-cancer pain on Relistor:
- Discontinue all maintenance laxative therapy prior to Relistor initiation 1
- If opioids have been used for less than 4 weeks, patients may be less responsive to Relistor 1
Common Pitfalls to Avoid
Do not confuse Relistor with naltrexone: Naltrexone requires much longer discontinuation periods (3-4 days for oral, 24-30 days for IM) because it is a centrally acting antagonist that will block postoperative opioid analgesia 2, 3
Do not restart Relistor if opioids are discontinued: The FDA label is explicit that Relistor should be discontinued if opioid treatment is stopped 1
Monitor for opioid withdrawal symptoms: While Relistor is peripherally acting, symptoms consistent with opioid withdrawal can still occur, including sweating, chills, diarrhea, and abdominal pain 1
Watch for severe diarrhea: Discontinue Relistor if severe or persistent diarrhea develops 1