Diacerhein is one of the anthraquinones. Anthraquinones are organic compounds derived from plants and animals. They occur naturally in some plants, such as aloe and senna, as well as in fungi, lichens, and insects. Anthraquinones serve as a basic skeleton for these organisms' pigments. Humans have used these substances for centuries for their laxative properties as well as for the production of dyes.
Recently, diacerhein has been used for the treatment of OA by practitioners of alternative medicine. In animal studies, these compounds have been shown to have anti-inflammatory properties as well as a protective effect on cartilage. It is not yet clear whether diacerhein is both safe and effective in humans, however.
Investigators have reviewed seven studies that enrolled people with OA who were treated with diacerhein. These studies included 2069 patients with OA who received diacerhein; these individuals were compared to another group of patients with OA who were treated with a placebo (i.e., sugar pills). When investigators evaluated the group treated with diacerhein, they found that those patients had a statistically significant decrease in pain in the hips and knees.
When x-rays of the patients' hips were compared, researchers found a statistically significant slowing of the progression of OA. Evaluations of knee x-rays did not show this benefit. The most frequent adverse event experienced by patients in the diacerhein-treated group was diarrhea.
Overall, for the treatment of OA, these studies demonstrated a small, consistent benefit from taking diacerhein. The long-term effects of taking this compound have not been examined.