In a study of 148 patients with mild to moderate osteoarthritis of the knee, combination therapy of glucosamine plus diacerein did not improve pain scores compared with glucosamine monotherapy.
Patented crystalline glucosamine sulfate (pCGS) and diacerein are each recommended as separate monotherapies for patients with mild to moderate osteoarthritis (OA), Kongtharvonskul and colleagues wrote. Because pCGS has an anabolic effect and diacerein has a catabolic effect, the researchers hypothesized combination therapy could improve pain and function compared with pCGS monotherapy.
To test this hypothesis, the researchers performed a double-blind, parallel, randomized controlled superiority trial between 2013 and 2014 in Thailand. They assessed 148 patients (mean age, 60 years) who received either combination therapy (n = 74) or monotherapy with placebo (n = 74). Patients had a Kellgren-Lawrence grade of 2 or 3. After 24 weeks of treatment, the researchers examined the VAS and WOMAC scores.
The average VAS score was 2.97 for combination therapy and 2.88 for monotherapy. For combination therapy, the WOMAC score was 12.02 for pain; 32.74 for function; 3.85 for stiffness; and 48.59 total compared with monotherapy scores of 11.76, 32.47, 4.16 and 48.69, respectively. For the adverse event of diarrhea and dyspepsia, the risk ratio was 1.03 for combination therapy and 0.91 for monotherapy.
The researchers noted the similarity of these findings to a previous study that showed the lack of improvement for the combination therapy of pCGS plus chondroitin sulfate compared with chondroitin sulfate monotherapy. – by Will Offit
Disclosure: The researchers report no relevant financial disclosures.