Research progress on the effects of opioids on the immune system

Opioids are excellent analgesics for the clinical management of a wide range of acute and chronic pain, especially cancer-related pain. Opioids are known to have some serious side effects, including respiratory depression, constipation, and addiction. In recent years, the population of opioid users has become progressively larger, and more and more studies have begun to focus on their suppressive effects on the immune system. There are currently no effective medications to alleviate opioid-induced immunosuppression. Understanding the mechanisms by which the immune system is impaired could lead to more rational guidance for clinical use and the design of effective therapeutic interventions. This article reviews the effects and mechanisms of opioids on the immune system, and describes their use in inflammatory immunity and tumor immunity, to provide some guidance for clinicians in the use of drugs.