Cautions

Opioid toxicity

• Can be precipitated by several factors, including rapid dose escalation, renal impairment, sepsis, electrolyte abnormalities, drug interactions.
• Wide variation in the dose of opioid that can cause symptoms of toxicity.
• Prompt recognition and treatment are needed. Symptoms include:
• persistent sedation (exclude other causes)
• vivid dreams/hallucinations; shadows at the edge of visual field
• delirium
• muscle twitching/myoclonus/jerking
• abnormal skin sensitivity to touch (opioid induced hyperalgesia, OIH).
• If the pain is controlled, reduce the opioid dose by a third. Ensure the patient is well hydrated. Seek advice.
• If pain is uncontrolled, consider reducing opioid dose by a third. Consider adjuvant analgesics, alternative opioids or both. Seek advice.
• Naloxone (in small titrated doses) is only needed for life-threatening respiratory depression (refer to Naloxone guideline).