Opioid withdrawal

• Commonly Methadone is started at 20-30mg for moderate to severe opiate withdrawal but this needs to be prescribed with drug health service advice
• Buprenorphine (partial opioid agonist) can also be used for opioid withdrawal but it can precipitate withdrawal if there are still opioids on board. This should be guided and prescribed with Drug Health. In many respects it is safer than Methadone

Acute pain and the patient is on methadone or buprenorphine

• Continue Buprenorphine or Methadone at normal dose
• May need larger than normal doses of short acting opioids, such as morphine, because they have tolerance and receptor occupancy. A larger doe is needed to overcome the competitive effect at the receptor
• Patients with opioid dependence often have their pain under-treated
• Use multimodal analgesia with paracetamol and NSAIDS

What if the patient is also nil by mouth?

• Don’t withhold IV Morphine and PCA’s from patients in acute pain
• Methadone can be given sub cut but this MUST be guided by pharmacy and Drug Health as the dose can be different
• Buprenorphine can be given sublingually so it doesn’t need to be changed if the patient is NBM

Opioid overdose or toxicity

• Naloxone is the antidote for opioid toxicity
• Toxicity may be delayed if the opioid has along half life like Methadone
• Giving Naloxone to the opioid toxic patient:
  • Peri-arrest or opioid naive patient with opioid toxicity can give 400mcg IV
  • Beware of precipitating withdrawal in the opiate dependent patient. Consider giving smaller doses and titrating 40-80mcg at a time
  • Naloxone is shorter acting than most opioids and repeat doses or infusions may be required

• Opioid withdrawal is very unpleasant but not life threatening
• Addiction and drug health services should be consulted before prescribing methadone or buprenorphine and can provide useful advice about acute pain management in the opiate dependent patient