Duration to Hold Naltrexone Before Anesthesia
For oral naltrexone, discontinue 2-3 days before elective surgery if opioids will be needed perioperatively; for extended-release naltrexone (Vivitrol), discontinue 24-30 days after the last injection. 1
Oral Naltrexone Timing
- Hold oral naltrexone for 2-3 days prior to elective surgical procedures when perioperative opioid use is anticipated. 1
- The plasma half-life of naltrexone is 4 hours, but its active metabolite (6-β-naltrexol) has a 13-hour half-life that accumulates during long-term therapy, causing antagonist effects to persist for 2-3 days after stopping. 1, 2
- This 2-3 day washout period allows sufficient clearance of both naltrexone and its active metabolite to restore opioid receptor responsiveness for adequate perioperative analgesia. 1
Extended-Release Naltrexone (Vivitrol) Timing
- Extended-release naltrexone must be held for 24-30 days after the last injection before elective surgical procedures if opioids are expected to be used perioperatively. 1
- The prolonged duration of action from the depot formulation requires this extended washout period to ensure opioid analgesics will be effective. 1
- Patients on extended-release naltrexone who require urgent surgery may experience inadequate pain control from opioids and need alternative analgesic strategies including regional anesthesia, non-opioid systemic agents, or general anesthesia techniques that minimize opioid requirements. 3
Critical Clinical Pitfalls
- Patients who have not been off naltrexone for adequate duration may be completely refractory to opioid analgesia, requiring significantly higher opioid doses that can lead to serious complications including respiratory depression once the naltrexone blockade wears off. 4
- Some patients on long-term extended-release naltrexone may develop opioid receptor upregulation, paradoxically making them more sensitive to dangerous opioid side effects (particularly respiratory depression) when the blockade is overcome. 1, 4
- Patients discontinuing naltrexone are at markedly increased risk of opioid overdose and death due to loss of opioid tolerance during treatment, requiring careful counseling about this risk. 3, 5
- If naltrexone cannot be discontinued for the recommended duration before urgent/emergent surgery, inform the anesthesiologist immediately so alternative pain management strategies can be implemented. 1
Verification Before Surgery
- Confirm the patient has been completely opioid-free (including tramadol) for a minimum of 7-10 days before starting naltrexone to avoid precipitated withdrawal when restarting postoperatively. 5
- Document the exact date of the last naltrexone dose (oral) or injection (extended-release) to calculate appropriate washout time. 1
- Consider a naloxone challenge test if there is uncertainty about adequate opioid-free period, though this should not be performed in patients showing clinical signs of withdrawal or with opioids detected in urine. 5
Alternative Analgesic Strategies When Inadequate Washout Time
- Employ multimodal analgesia with non-opioid agents including acetaminophen, NSAIDs, gabapentinoids, ketamine, and regional anesthesia techniques. 3, 6
- General anesthesia alone (without reliance on opioid analgesia) may be necessary for surgical procedures. 3
- Be prepared that even with these strategies, pain control may be inadequate if naltrexone blockade persists. 6