To evaluate the efficacy and safety of Harpagophytum in the treatment of hip and knee osteoarthritis comparatively with the slow-acting drug for osteoarthritis, diacerhein.
A multicenter, randomized, double-blind, parallel-group study was conducted in 122 patients with hip and/or knee osteoarthritis. Treatment duration was four months and the primary evaluation criterion was the pain score on a visual analog scale. Harpagophytum 2,610 mg per day was compared with diacerhein 100 mg per day.
After four months, considerable improvements in osteoarthritis symptoms were seen in both groups, with no significant differences for pain, functional disability, or the Lequesne score. However, use of analgesic (acetaminophen-caffeine) and nonsteroidal anti-inflammatory (diclofenac) medications was significantly reduced in the Harpagophytum group, which also had a significantly lower rate of adverse events.
In this study, Harpagophytum was at least as effective as a reference drug (diacerhein) in the treatment of knee or hip osteoarthritis and reduced the need for analgesic and nonsteroidal anti-inflammatory therapy.