More opioids, more pain: Fueling the fire

For more than a century, clinicians have noticed a paradoxical phenomenon: certain patients who are taking opioids (which are supposed to numb pain) become more sensitive to pain than those who are not taking opioids. The earliest observation of this phenomenon can be traced back to the British physician Sir Clifford Allbutt, who, in 1870, described it: “at such times I have certainly felt it a great responsibility to say that pain, which I know is an evil, is less injurious than morphia, which may be an evil. Does morphia tend to encourage the very pain it pretends to relieve?” Research studies and clinical observations over the years have identified the phenomenon Dr. Allbutt noticed as opioid-induced hyperalgesia (OIH). What is opioid-induced hyperalgesia? Hyperalgesia is an increased pain response from a stimulus (cause) that usually provokes a minor pain response. For example, getting your blood drawn for lab testing usually causes mild discomfort, but this common medical procedure would be very painful for certain patients who are taking opioids chronically. OIH is a lesser known side effect of long-term opioid therapy, but a serious one, and yet another reason doctors should carefully select who may benefit from extended use of these pain medications. What causes OIH? The mechanism behind opioid-induced hyperalgesia is complex and involves molecular and chemical changes in the brain and spinal cord. Opioids tend to activate specific receptors that block painful sig...
Source: Harvard Health Blog - Category: Consumer Health News Authors: Tags: Pain Management Source Type: blogs