A Randomized Controlled Trial of Thai Medicinal Plant-4 Cream versus Diclofenac Gel in the Management of Symptomatic Osteoarthritis of the Knee

BACKGROUND: Osteoarthritis of the knee is a common degenerative musculoskeletal condition. Thai Medicinal Plant-4 (TMP-4) cream is made up of Garcinia mangostana peel, Sesamum indicum seeds, Glycine max (L.) Merr. seeds, and Centella asiatica leaves, all of which have anti-inflammatory and analgesic properties. The present study aimed at determining the efficacy and safety of TMP-4 cream versus diclofenac gel in the treatment of symptomatic osteoarthritis of the knee. METHODS: A randomized-controlled trial was conducted to assess knee pain on a scale of 100 mm Visual Analog Scale (VAS) and other key metrics, including VAS knee stiffness, a modified 10-step stair climb test, a timed up and go test, the Knee Injury and Osteoarthritis Outcome Score, and safety outcomes, following administration of either TMP-4 cream or diclofenac gel for 4 weeks. RESULTS: A total of 199 patients with moderate knee pain intensity were randomly assigned to either TMP-4 cream or diclofenac gel (allocation ratio 1 : 1). The mean changes of VAS knee pain in the TMP-4 cream and diclofenac gel groups were −31.68 ± 14.18 mm and −31.09 ± 12.41 mm, respectively, (mean difference = −0.58, 95% confidence interval = −4.37–3.20, P=0.761). The upper limit of 95% confidence interval for the comparison between TMP-4 cream and diclofenac gel was within the predefined margin of 7 mm for noninferiority. The safety was comparable between the two interventions. CONCLUSIONS: TMP-4 cream was noninferior to diclofenac gel in relieving osteoarthritic knee pain and may be considered as an alternative therapeutic option in the treatment of symptomatic osteoarthritis of the knee.