A Crucial Administration Timing Separates Between Beneficial and Counterproductive Effects of Opioids on Postoperative Pain

Erica Suzan; Dorit Pud; Elon Eisenberg


Pain. 2018;159(8):1438-1440. 

In This Article


Tissue injury leads to sensitization of peripheral and central pain pathways, which in turn, enhances clinical pain, including acute postoperative and posttraumatic pain. Indeed, studies have shown that painful surgical procedures, mainly but not only those involve nerve injuries, sensitize pain pathways and often result in high levels of postoperative pain.[21] Not surprisingly, about two-thirds of patients who undergo surgery report moderate to severe early postoperative pain.[7]

In an attempt to attenuate sensitization of pain pathways and subsequent postoperative pain, analgesic techniques and drugs are often used either before, during, or after surgery. This includes opioid drugs, which are often administered chronically for the management of chronic (sometimes preoperative) pain, preemptively (immediately before surgery has begun), during surgery (while tissue injury is ongoing) or postoperatively for managing already existing pain.

Although the role of opioid therapy in managing chronic pain is controversial, there is a clear consensus regarding using opioids as the most effective weapon for controlling acute moderate to severe pain around surgery, in many patients.[3] However, in this article, we present a new concept, which identifies a crucial administration timing that separates between beneficial and counterproductive effects of opioids on postoperative pain: if administered before surgery ends—either chronically, preemptively, or during surgery opioids produce unfavorable outcome, measured by increased postoperative pain intensity and/or by higher opioid consumption. This is in strict contrast to their analgesic effect when administered after surgery has ended. Although observations on each of these unfavorable effects have already been reported separately, the broader aspect of this new concept is that if present in central pain pathways while injury occurs, opioids augment acute postoperative pain.