Harpagophytum procumbens in the treatment of knee and hip osteoarthritis. Four-month results of a prospective, multicenter, double-blind trial versus diacerhein

OBJECTIVE: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.