Title: Opioid Induced Hyperalgesia

Category: Toxicology

Keywords: Opioid, methadone, pain management, tolerance, analgesia (PubMed Search)

Posted: 6/6/2013 by Ellen Lemkin, MD, PharmD

Opioid analgesia can actually INCREASE sensitivity to pain in some cases

The exact cause is unclear, but may be due to up-regulation of NDMA receptors in spinal cord dorsal horn neurons

Pain tends to be DIFFERENT and DIFFUSE from the underlying condition for which the narcotics were prescribed

Switching from shorter acting opiates to methadone may be effective, as it is a weak NDMA antagonist and has only partial cross tolerance with other opioids

References

Gussow, L. Toxicology Rounds. When Opioids Increase Pain. Emergency Medicine News Feb 2013. 35(2):6.