More opioids, more pain: Fueling the fire

For greater than a century, clinicians have seen a paradoxical phenomenon: sure sufferers who’re taking opioids (that are speculated to numb ache) develop into extra delicate to ache than those that will not be taking opioids.

The earliest commentary of this phenomenon will be traced again to the British doctor Sir Clifford Allbutt, who, in 1870, described it: “at such occasions I’ve definitely felt it an awesome duty to say that ache, which I do know is an evil, is much less injurious than morphia, which can be an evil. Does morphia are inclined to encourage the very ache it pretends to alleviate?” Analysis research and scientific observations over time have recognized the phenomenon Dr. Allbutt seen as opioid-induced hyperalgesia (OIH).

What’s opioid-induced hyperalgesia?

Hyperalgesia is an elevated ache response from a stimulus (trigger) that normally provokes a minor ache response. For instance, getting your blood drawn for lab testing normally causes delicate discomfort, however this widespread medical process could be very painful for sure sufferers who’re taking opioids chronically. OIH is a lesser identified aspect impact of long-term opioid remedy, however a critical one, and but another excuse docs ought to fastidiously choose who might profit from prolonged use of those ache medicines.

What causes OIH?

The mechanism behind opioid-induced hyperalgesia is advanced and includes molecular and chemical adjustments within the mind and spinal twine. Opioids are inclined to activate particular receptors that block painful indicators from reaching the mind. When these medicines are taken for lengthy durations of time, our our bodies (as a protection mechanism) attempt to overcome these blocked indicators by activating different ache indicators and pathways, a phenomenon referred to as hypersensitization. These adjustments mirror the unbelievable talents of our brains to type new connections and pathways and alter how the circuits are related in response to adjustments, also called neuroplasticity. A constructive instance of this could be the rehabilitation course of after a stroke: when somebody suffers a stroke on account of a clot or bleed within the mind and turns into unable to make use of their arm correctly, the mind will begin forming new connections in an try to beat this deficit, and with correct rehabilitation and coaching an individual might be able to use the arm usually once more.

Who’s liable to growing OIH?

Ache notion is a really advanced course of. Many elements have an effect on how the mind interprets ache indicators. Anxiousness, despair, genetics, medicines, our bodily well being, and different diseases can enhance or lower our feeling of ache. Simply as ache notion is particular person, the extent of hyperalgesia is just not the identical in all sufferers; some individuals will expertise extra hyperalgesia based mostly on their genetics and private predisposition. Moreover, there isn’t a well-established interval of publicity after which OIH happens, and the precise timing of somebody growing OIH varies from patient-to-patient.

What we do know is that individuals who take opioids recurrently are at better threat of growing OIH. Researchers have checked out many sufferers who had been taking opioids for lengthy durations of time and in contrast their ache tolerance or ache sensitivity to that of sufferers who weren’t taking opioids. Researchers additionally in contrast sufferers’ ache sensitivity earlier than and after beginning opioid remedy. In each circumstances they discovered that administration of opioids paradoxically elevated sensitivity to ache and made pre-existing ache worse, and better doses of opioids had been related to increased sensitivity to ache.

Recognizing and treating OIH

For those who or your physician aren’t conscious of this phenomenon, and you’re prescribed extra opioids to deal with elevated ache sensitivity, it could result in a vicious cycle of accelerating the dose of opioids and extra ache, in addition to an elevated threat of overdose. The suitable strategy to treating OIH is to wean slowly from a excessive dose of opioids, which normally requires time and persistence. Throughout this time, it might be acceptable so as to add non-opioid alternate options to managing ache, reminiscent of different medicines, injections, behavioral interventions, and bodily remedy. You physician may additionally advocate avoiding opioids altogether, or taking an “opioid vacation” so your physique can get well. Working carefully along with your healthcare workforce is essential, as is managing your ache throughout a weaning interval. There are CDC tips out there to assist your physician safely taper your dose.

Traditionally, opioids had been used to deal with ache attributable to end-stage superior most cancers, or for acute ache (after surgical procedure, a bone fracture, a critical accident, and many others.), and just for a brief time frame (a number of days), to scale back the danger of unintended effects. Sadly, there was a drastic enhance in using opioids in america over the past 20 years for the therapy of power non-cancer ache (again ache, arthritis, and many others.), and a few individuals have taken opioids for longer than medically crucial for his or her sort of ache.

Whereas opioids positively have their place in medical apply, we’d like to concentrate on the intense unintended effects of those medicines, together with unintended effects which will trigger extra struggling, like OIH, in addition to deadly unintended effects reminiscent of overdose. For those who suppose you or a liked one could also be experiencing OIH, it’s best to focus on this with you physician, and work with them to taper your dose and discover alternate options to handle your ache safely.


A Complete Overview of Opioid-Induced Hyperalgesia. Ache Doctor, March/April 2011.

Opioid-induced Hyperalgesia: A Qualitative Systematic Overview. Anesthesiology, March 2006.

Opioid Induced Hyperalgesia. Ache Drugs, October 2015.

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