Does diacerein work to treat osteoarthritis and is it safe?
Seven studies of moderate to high quality were reviewed and provide the best evidence we have today. The studies tested over 2000 people with osteoarthritis of the hip or knee. The studies compared people who took 100 mg of diacerein to people who took a placebo (fake pill), or non-steroidal anti-inflammatory drugs (NSAIDs) or other slow acting arthritis drugs. The studies lasted 2 months to 3 years.
What is osteoarthritis and could diacerein work?
Osteoarthritis (OA) is the most common form of arthritis that can affect the hands, hips, shoulders and knees. In OA, the cartilage that protects the ends of the bones breaks down and causes pain and swelling. Drug and non-drug treatments are used to relieve pain and/or swelling. Diacerein is a slow-acting drug taken as a pill that may slow down the breakdown of cartilage and relieve pain and swelling. It may also be safe on the stomach. It is not clear whether diacerein works and whether it is safer than other drugs used to treat OA.
What did the studies show?
Pain improved about the same whether people took diacerein, a placebo, NSAIDs or other slow acting drugs. But, pain does seem to improve a bit more in people who take diacerein.
Pain decreased by about 5 more points on a 0-100 scale for people who took diacerein than a placebo.
One study shows that pain, stiffness, and physical function overall improved more in people who took diacerein than a placebo.
Two long term studies which lasted 1 year and 3 years measured the progress of the disease on x-rays. The studies found that diacerein slowed the progress in OA of the hip more than a placebo but did not slow the progress in OA of the knee.
How safe is diacerein?
Side effects such as diarrhoea, heartburn, soft stools, stomach pain and frequent bowel movements. Diarrhoea was the most common side effect and usually occurred during the first two weeks of starting diacerein.
42 out of 100 people who took diacerein had diarrhoea. 18 out of 100 people who took diacerein withdrew from the studies due to side effects compared with 13 out of 100 people in the placebo group.
What is the bottom line?
The level of quality of the evidence is 'gold'. It appears that diacerein has a small effect in improving pain and slowing the progress of osteoarthritis (in the hip). Diarrhoea is a common side effect of diacerein.
Longer studies need to be done to determine the long term benefits and harms of diacerein.