Long-term use of opioids for complex chronic pain.

Increased opioid prescribing for back pain and other chronic musculoskeletal pain conditions has been accompanied by dramatic increases in prescription-opioid addiction and fatal overdose. Opioid-related risks appear to increase with dose. Although short-term randomised trials of opioids for chronic pain have found modest analgesic benefits (a one-third reduction in pain intensity on average), the long-term safety and effectiveness of opioids for chronic musculoskeletal pain remains unknown. Given the lack of large, long-term randomised trials, recent epidemiologic data suggest the need for caution when considering long-term use of opioids to manage chronic musculoskeletal pain, particularly at higher dosage levels. Principles for achieving more selective and cautious use of opioids for chronic musculoskeletal pain are proposed.