Chronic exposure to opioids may cause hypersensitivity to pain

The Prescription Review Program has noticed increased prescribing of hydromorphone. Physicians should be aware that chronic exposure to opioids, including hydromorphone, may cause hypersensitivity to pain. Recent research published in the Pain Physician journal suggests a positive correlation between opioid-induced hyperalgesia and hydromorphone dosage.¹

Although the authors of the study acknowledge the limitations of their research (it was not a randomized, controlled trial), their findings serve as an important reminder to physicians of the challenges they face when prescribing opioids. Whether the challenge is opioid-induced hyperalgesia or another issue, the College’s medical reviewers often observe cases of concerning opioid prescribing. Often, the problem has its origins in initial treatment decisions that were not based on a prudent approach to treating chronic non-cancer pain. 

While physicians must take into account the clinical situation of specific patients, the Prescription Review Program advises them to consider the following general principles:

  • Start low and go slow. If there is no compelling improvement in pain relief with functional benefit early, then it is reasonable to discontinue the trial. 
  • Risk is strongly associated with dose—more overdoses occur with doses greater than 100 mg morphine-equivalent daily dose.
  • Doses above 200 mg morphine-equivalent daily dose are not scientifically valid and increase the risk of adverse effects including opioid-induced hyperalgesia, mood disruption, sleep disturbance, hormonal dysregulation, and gastrointestinal dysfunction.
  • For patients on a mix of drugs including opioids, sedatives, anticonvulsants, and antidepressants, there is no empirical evidence that this is safe or effective. Rather, these combinations greatly increase the risk of adverse effects. 

Physicians are advised to review the Prescription Review Committee’s Prescribing Principles for Non-Cancer Pain and to consider how they could alter their practices to align with the College’s expectations in this area. 

1.    Elon Eisenberg, M. (2013). A negative correlation between hyperalgesia and analgesia in patients with chronic radicular pain: is hydromorphone therapy a double-edged sword?. Pain physician, 16, 65-76.