5th January 2024

Opioid Toxicity

Features of Opioid Toxicity

• Hallucinations
• Confusion
• Extreme drowsiness
• Myoclonus
• Respiratory depression

Interestingly, opioids can increase the end tidal volume, so a reduction in respiratory rate does not always correlate with a decrease in oxygen saturation. Features of opioid toxicity requiring immediate reversal in the palliative patient are a respiratory rate of 8 or less, abnormal oxygen saturations, or any signs of cyanosis. In the palliative care setting, naloxone is not indicated for use in drowsiness that is not life-threatening.

Naloxone

If opioid reversal is indicated, 400 micrograms of the reversal agent naloxone should be diluted and given as a slow IV bolus at 80 micrograms at a time. It is rare that the full dose will need to be used.

Naloxone should be used cautiously to help prevent immediate return of pain. When too high a dose is given in patients who are established on opioids, it can also lead to significant acute withdrawal reactions that can cause life-threatening tachycardia, arrhythmia, hypertension and arrest.