Gabapentin and duloxetine were found to provide comparable analgesia and improvement in functional status in patients with knee osteoarthritis (OA) after 3 months of treatment, according to a study published in Clinical Rheumatology.
The study included participants with moderate to severe knee OA (n=150) who were randomly assigned to receive duloxetine 30 mg (n=50), gabapentin 300 mg (n=50), or acetaminophen 1000 mg (n=50) twice a day for 12 weeks. Pain severity was assessed with a visual analog scale (VAS), and functional status was evaluated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline, 2 weeks, 1 month, and 3 months after treatment.
At 2 weeks and 1 month after initiating treatment, participants who received duloxetine vs gabapentin had lower WOMAC total and subscale scores. However, after 3 months of treatment, there was no significant difference between the 2 groups. Participants who received gabapentin or duloxetine vs acetaminophen had greater reductions in VAS, WOMAC total, and WOMAC subscale scores.
Treatment-related adverse events were reported by 18% (n=9) of participants in the gabapentin group and 16% (n=8) of participants in the duloxetine group. In the gabapentin group, participants reported dry mouth (n=5), drowsiness (n=2), and fatigue (n=2). In the duloxetine group, participants reported drowsiness (n=5), fatigue (n=2), and dry mouth (n=1). No participants in the acetaminophen group reported any adverse events.
“Both gabapentin and duloxetine have similar and acceptable effects in pain reduction and improvement of functional status in patients with knee OA at the end of the third month’s treatment,” the researchers noted.
Enteshari-Moghaddam A, Azami A, Isazadehfar K, et al. Efficacy of duloxetine and gabapentin in pain reduction in patients with knee osteoarthritis [published online May 6, 2019]. Clin Rheumatol. doi:10.1007/s10067-019-04573-7