The role of opioid analgesics in rheumatic disorders: a position paper from the Portuguese Rheumatology Society.

Pain is a common feature of most rheumatic diseases and it is often the main reason for the patient to seek for a clinical appointment. Chronic pain has a major impact on patient's quality of life, being frequently associated with functional incapacity, sleep and mood disorders. This leads to absenteeism and heavy consumption of health resources, both representing huge burdens on national economy. Managing musculoskeletal pain is pivotal but can be challenging. The use of the available pharmaceutical armamentarium should be parsimonious. Opioids are strong analgesic drugs that mostly act through their agonist action on µ-receptors in the central nervous system. Opioid-related side effects are not negligible and are mediated through both central and peripheral opioid receptors. The use of opioids is well established in the treatment of oncologic pain but their role in the management of musculoskeletal pain is still controversial. Inflammatory rheumatic diseases, osteoarthritis, osteoporotic fractures, chronic low back pain and fibromyalgia represent diverse major rheumatic conditions that frequently lead to chronic pain. In order to standardize and optimize management of musculoskeletal chronic pain in these prevalent diseases, the Portuguese Rheumatology Society elaborated this position paper. The objectives were: a) to define the importance of pain assessment and classification; b) to guide patient selection, appropriate choice of opioids, their management, and raise awareness of their adverse effects; c) to review the existent data on possible indications of opioid therapy on rheumatic diseases.