Pharmacotherapy of chronic pain: a synthesis of recommendations from systematic reviews

Chronic pain is one of the most prevalent, costly and disabling conditions in both clinical practice and the workplace, yet often remains inadequately treated. Moreover, chronic pain commonly co-occurs with depression, anxiety and somatoform disorders, and adversely affects response of these conditions to psychiatric treatments. This article provides an evidence-based approach to the pharmacotherapy of chronic pain.This narrative review is derived largely from meta-analyses and systematic reviews published since 2005. For a few medications, findings from multiple recent trials are synthesized if a systematic review had not yet been published. Classes of medications are first reviewed, followed by an overview of four common pain disorders: neuropathic pain, low back pain, fibromyalgia and osteoarthritis.A stepped care approach based upon existing evidence includes (1) simple analgesics (acetaminophen or nonsteroidal anti-inflammatory drugs); (2) tricyclic antidepressants (if neuropathic, back or fibromyalgia pain) or tramadol; (3) gabapentin, duloxetine or pregabalin if neuropathic pain; (4) cyclobenzaprine, pregabalin, duloxetine, or milnacipran for fibromyalgia; (5) topical analgesics (capsaicin, lidocaine, salicylates) if localized neuropathic or arthritic pain; and (6) opioids. Disease-specific recommendations for neuropathic, low back, fibromyalgia and osteoarthritis pain are reviewed.A number of medications have proven effective in chronic pain disorders and their use individually or in combination should improve the management of chronic pain.