Study protocol for a randomised, double-blind, placebo-controlled clinical trial of duloxetine for the treatment and prevention of musculoskeletal pain: altering the transition from acute to chronic pain (ATTAC pain).

introductionChronic musculoskeletal pain affects a substantial portion of adults visiting the emergency department (ED). Current treatment is limited in scope and does not effectively reduce musculoskeletal pain in patients. The study will evaluate the use of duloxetine, a serotonin-norepinephrine reuptake inhibitor Food and Drug Administration approved for the treatment of chronic pain, as a promising option in its prevention. The proposed study may present a well-tolerated and effective non-opioid treatment for patients with acute musculoskeletal pain that may also be effective in preventing the transition to persistent or chronic musculoskeletal pain. METHODS AND ANALYSIS: The primary outcome of this study will be to assess the tolerability and preliminary effectiveness of duloxetine in patients with acute musculoskeletal pain. The study will take place at two EDs in Rhode Island, USA. The study will involve randomisation to one of three arms: duloxetine 30 mg, duloxetine 60 mg or placebo. Tolerability will be assessed by comparing the proportion of participants that report an adverse event and that drop-out across the three study arms. Effectiveness will be determined by self-reported pain over 6 weeks of follow-up. Specifically, we will compare the proportion of participants with persistent pain (ongoing pain at 6-week follow-up), across the three study arms. 60 adults (aged 18-59) presenting to the ED with acute axial musculoskeletal pain within 7 days of onset are expected to be enrolled in the proposed study. ETHICS AND DISSEMINATION: Ethics approval was obtained by the Institutional Review Board (IRB). These results will be published in a peer reviewed scientific journal and presented at one or more scientific conferences. TRIAL REGISTRATION NUMBER: NCT03315533.