Comparison of the effects of duloxetine and pregabalin on pain and associated factors in patients with knee osteoarthritis

OBJECTIVES: This study aimed to investigate the effects of duloxetine and pregabalin primarily on pain and functional status in patients with knee osteoarthritis and secondarily on quality of life, depression, anxiety, and sleep disturbance. METHODS: A total of 66 patients with knee osteoarthritis were randomized to use duloxetine or pregabalin. Patients were evaluated by Visual Analog Scale, Neuropathic Pain Diagnostic Questionnaire, Western Ontario and McMaster University Osteoarthritis Index, Short Form-36, Beck Depression Inventory, Beck Anxiety Inventory, and Pittsburg Sleep Quality Index before the treatment and after 4 and 12 weeks of treatment. RESULTS: Improvements occurred in Visual Analog Scale, Neuropathic Pain Diagnostic Questionnaire, Western Ontario and McMaster University Osteoarthritis Index, Short Form-36 (with an exception of the mental health subgroup scores in duloxetine-treated group), Beck Depression Inventory, and Beck Anxiety Inventory scores in both groups from 4 weeks after baseline. Pittsburg Sleep Quality Index total scores and SF-36 mental health subgroup scores started to improve on the 4th and 12th weeks in pregabalin-and duloxetine-treated groups, respectively. CONCLUSION: Osteoarthritis pain, a complex outcome with nociceptive and neuropathic components, leads to central sensitization in a chronic phase. Using centrally acting drugs in the control of pain and associated symptoms would increase the probability of treatment success.