Patients who receive high, escalating doses of opioids (for example: morphine or oxycodone) may experience an increase in pain as a result of their medication. This phenomenon, called Opioid Induced Hyperalgesia (OIH), is different than developing a tolerance to medication in several ways
- The nature of the pain is different than the pain for which the opioid was originally prescribed. Often, pain becomes more diffuse, or widespread.
- The location of the pain is different than the pain for which the opioid was originally prescribed, and often extends to more locations.
- The quality of the pain is different than the original pain. For example, the patient may experience allodynia, a condition in which normal sensation, such as touch, becomes painful.
- Pain sensitivity can increase
- Pain tolerance decreases
- Whereas patients who have developed opioid tolerance may have transient relief from additional opioids, patients with OIH will have an increase in pain from additional opioids.[1]
Theoretical explanations for OIH include the roles of microglia and mast cells. Though the mechanism by which this occurs isn’t fully understood yet, use of ultra low-dose Naltrexone has been reported to be effective in decreasing opioid side effects and facilitating reductions in dose. It is clear that long-term maintenance on opioids can do more harm than good for some patients. Therefore, it may be wise to periodically attempt to decrease the amount of opioids to see if this either results in no increase or an actual decrease in pain.
[1] Lee, Marion, Sanford Silverman, Hans Hansen, Vikram Patel, and Laxmaiah Manchikanti. “A Comprehensive Review of Opioid-Induced Hyperalgesia.” Pain Physician Journal (2011): n. pag. Print.
Filed under: opioids • pain management
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I see many patients who come to our clinic with high opioid doses. We try to help them go down in the dose and often it is seen that the pain becomes less and they become more alert. Unfortunately it is a very difficult and longlasting procedure because many of them have been on opioids for years. My advice: Don’t use opioids unless it is absolutely necessary and tell the patient to go out of the treatment once a year (even more often if possible) and keep “clean” at least 4 weeks. During this time it is possible to find out if it is necessary to start the treatment again or if the patient can manage the pain with other treatments. This method helps also to avoid the development of tolerance so that the dosis can be kept low and opioid induced hypealgesia is avoided.