Two Cases of Opioid-Induced Hyperalgesia in Cancer Patients Treated with Opioids for Pain Management

Abstract

Opioids are important drugs for the management of severe cancer pain without a ceil-ing effect. However, opioid administration leads to dose-limiting complications including drowsiness, hallucinations, delirium, respiratory depression, cognitive impairment, seizure, myoclonus, and hyperalgesia. Opioid-induced hyperalgesia (OIH) is a paradoxical phe-nomenon as opioid exposure increases pain sensitivity. Reducing or stopping opioids, opioid rotation, or co-administration of N-methyl-D-aspartate (NMDA) antagonists have been suggested for the management of OIH. In this study, we report two clinical cases of suc-cessful management of OIH in cancer pain patients that were treated with opioids.