[Double-edged sword of opioids in the treatment of cancer pain: hyperalgesia].

Hyperalgesia is an occult complication during the treatment of cancer pain, not only related to opioids, but also pertaining to the tumor itself and cancer therapeutic drugs. Yet it is often ignored by clinicians. Patients with cancer pain who were treated with opioids often have sensory abnormalities presented with reduced pain threshold and increased sensitivity to nociceptive stimuli. This phenomenon is clinically called opioid-induced hyperalgesia (OIH). However, due to the complexity of pathogenesis and the lack of clinical diagnostic criteria, the pain management of cancer patients is still facing great challenges. Therefore, this article focuses on the clinical diagnosis, pathogenesis, prevention and treatment of hyperalgesia related to cancer pain treatment, in order to provide a basis for optimal use of opioids in the future.