Opioid Analgesics Adverse Effects: The Other Side of the Coin

Background: Opioids are the cornerstone of the management of cancer pain. However, the development of adverse effects may compromise the opioid response. They include nausea and vomiting, constipation, drowsiness, sleep disorders, cognitive dysfunction, myoclonus, pruritus, dysuria, dependence and the development of aberrant behaviors, respiratory depression, and some endocrine responses. Methods: The goal of this paper is to identify the most common opioid-related adverse effects, their pathophysiology, and proposing the possible treatments. This narrative review will describe how these adverse effects may develop and how to prevent or to treat. Conclusion: Intensity of adverse effects tend to decrease with continuous use. However, they may be persistent and may require symptomatic treatment or more complex treatment including alternative strategies for pain management.