Safety and efficacy of Curcumin versus Diclofenac in Knee Osteoarthritis: a randomized open label parallel arm study

Abstract Background: To compare the efficacy and safety of curcumin with diclofenac in the treatment of knee osteoarthritis (OA). Methods: In this randomized, open label, parallel, active controlled clinical study, 139 patients of knee OA were randomized to receive either Curcumin 500 mg (Curcugreen®) capsule thrice daily or diclofenac 50 mg tablet twice daily for 28 days. Patients underwent assessment at baseline, day 7, day 14 and day 28. Primary efficacy measures were severity of pain (Visual Analogue Scale) and the Knee injury and osteoarthritis outcome score (KOOS) subscale at day 14 and day 28. Anti-flatulent effect (at day 7), anti-ulcer effect, weight lowering effect, patient and physician’s global assessment of therapy at day 28 were included as secondary endpoints. Safety after treatment was evaluated by recording adverse events and laboratory investigation. Results: Both treatment groups showed similar improvement in primary endpoints at day 14 and day 28. Patients receiving curcumin showed similar improvement in severity of pain and KOOS scale when compared to diclofenac, and the difference was not statistically significant (p>0.05). On day 7, the patients treated with curcumin experienced significantly greater reduction in number of episodes of flatulence compared with diclofenac (p<0.0001). Similar trend was observed at day 28 for weight lowering effect of curcumin (p<0.0001) and anti-ulcer effect. None of the patients required H2 Blockers in curcumin group and 19 patients required H2 blockers in diclofenac group (0% Vs 28%, respectively; p<0.00001). Adverse effects were significantly less in curcumin group (13% vs. 38% in diclofenac group; p=0.0015). Patient’s and physician’s global assessment of therapy was similar towards both the treatment. Conclusion: Curcumin has similar efficacy, but better tolerated than diclofenac among patients with knee OA. Curcumin can be an alternative treatment option in the patients of knee OA who are intolerant to the side effects of NSAIDS. Trial Registration: ISRCTN, ISRCTN10074826, Registered 21 November 2017 - Retrospectively registered, http://www.isrctn.com/ISRCTN10074826 Keywords: Knee osteoarthritis; Pain; Curcumin; Diclofenac; Anti-flatulent; Weight lowering; Anti-ulcer