Opioids in chronic musculoskeletal conditions.

The use of opioids for benign disorders has been limited by concerns about these compounds' potential adverse events and their possible misuse. However, during the last few years an increased use in nonmalignant disorders, including rheumatologic diseases, has been observed. Herein, we review the scientific evidence for opioid therapy in three common scenarios in clinical rheumatology. Low back pain is a very frequent reason for consultation. Overall, the large majority of studies show a positive, yet rather moderate, effect of opioids in pain control, as well as in other outcomes including mood, work disability and anxiety. Similarly, opioids seem to have a role in the management of hip and knee osteoarthritis; indeed, they have been included in all international guidelines for the treatment of these conditions. However, clinical studies addressing opioid use in clinical situations are plagued by methodological limitations; furthermore, the large majority of these studies only provide short-term information about opiod utilization in these patients. Finally, opioids are currently being used as complementary therapy in inflammatory joint conditions whereby they may significantly improve the quality of life of some of these patients. Regarding their safety, severe adverse events, including abnormal drug-seeking behaviour, are very rare, but mild adverse events are frequent leading to drug discontinuation in a significant number of cases.