What is opioid-induced hyperalgesia?

Opioid-induced hyperalgesia refers to a condition where an individual experiences increased sensitivity to pain, even while being treated with opioid medications. This phenomenon can occur despite the administration of opioids, which are typically expected to relieve pain. The underlying mechanism may involve changes in the central and peripheral nervous systems due to prolonged opioid exposure. As the opioids act on the receptors, the body may become sensitized, leading to an amplified pain response rather than alleviation.

In contrast, increased tolerance to opioids refers to a situation where over time, a person requires higher doses to achieve the same level of pain relief; this does not involve an increase in pain perception itself. Reduced sensitivity to pain would be the expected outcome when opioids are effectively managing pain, which is contrary to the definition of hyperalgesia. Immediate withdrawal symptoms pertain to the physical and psychological reactions that occur when opioid use is reduced or stopped abruptly, rather than an increase in pain sensitivity. Understanding these distinctions is crucial for recognizing and managing opioid-induced hyperalgesia effectively in clinical practice.