Are there contraindications to restarting methadone for a patient who stopped it 1-2 days due to vomiting?

Restarting Methadone After Brief Discontinuation Due to Vomiting

Methadone can be safely restarted at the same dose after a 1-2 day discontinuation due to vomiting, as there are no contraindications to resuming therapy in this short timeframe. The brief interruption is unlikely to have significantly reduced the patient's opioid tolerance.

Assessment Before Restarting

Before restarting methadone, assess:

• Resolution of vomiting
• Hydration status
• Ability to tolerate oral medications
• Signs of withdrawal (if present)

Restart Protocol

For Patients on Maintenance Therapy:

• If no withdrawal symptoms are present: Resume the regular prescribed dose
• If mild withdrawal symptoms are present: Resume the regular prescribed dose
• If moderate to severe withdrawal symptoms are present: Consider splitting the daily dose into 2-3 smaller doses throughout the first day to minimize potential side effects

For Patients on Methadone for Pain Management:

• Resume the previous dose schedule, potentially dividing the daily dose into 3-4 smaller doses on the first day 1
• Monitor for adequate pain control and adjust as needed

Special Considerations

• Vomiting etiology: Ensure the cause of vomiting has been addressed before restarting methadone

• Antiemetic therapy: Consider prophylactic antiemetics when restarting methadone if vomiting was drug-related

  • First-line options include dopamine receptor antagonists such as prochlorperazine, haloperidol, or metoclopramide 2
  • For persistent nausea, consider 5-HT3 receptor antagonists like ondansetron (with caution due to potential QT prolongation) 1, 2

• QT prolongation risk: For patients on high doses of methadone (>100 mg/day) or with cardiac risk factors, consider ECG monitoring when restarting after even brief discontinuation 1, 3

Monitoring After Restart

• Observe for signs of:
  • Oversedation
  • Respiratory depression (rare with brief discontinuation)
  • Recurrence of vomiting
  • Inadequate withdrawal management

Potential Pitfalls to Avoid

1. Dose reduction: Unnecessarily reducing the methadone dose after only 1-2 days of discontinuation may lead to inadequate treatment and withdrawal symptoms

2. Delayed restart: Waiting too long to restart methadone can precipitate unnecessary withdrawal symptoms

3. Failure to address underlying cause: Not identifying and treating the cause of vomiting may lead to recurrence

4. Inadequate monitoring: Patients should be monitored for both withdrawal symptoms and potential oversedation when restarting

Remember that methadone's long half-life (15-60 hours) means that after only 1-2 days of discontinuation, significant amounts of the drug likely remain in the patient's system, making an abrupt loss of tolerance unlikely 1, 4.