Brain-Based and Clinical Phenotyping of Pain Pharmacotherapy in Knee Osteoarthritis

This longitudinal study will screen and enroll 180 participants diagnosed with knee osteoarthritis at Northwestern University Feinberg School of Medicine. The study will last for about 20 weeks' duration with a repeat-treatment design. An equal number of participants (60 per group) will be randomly assigned in a 1:1:1 ratio, stratified by sex and current opioid use, to one of three treatment groups after they qualify to enter the study. The treatment groups will celecoxib (200 mg qd), duloxetine (60 mg qd, with an initial and final 7-day titration at 30 mg qd), or matching placebo (one capsule qd). This aim of this study is to identify specific biomarkers in individual people with knee osteoarthritis pain that will allow definition of responder phenotypes distinct for different therapeutic interventions.