Efficacy and safety of diacerein in the treatment of patients with painful knee osteoarthritis: A modified regimen

Abstract

Background : Recent systematic meta-analyses provide evidence for the efficacy of diacerein 100 mg/day in the treatment of knee and hip osteoarthritis (OA). However, as diacerein may cause acceleration in intestinal transit time during the first 2 weeks of treatment, it is recommended to start with 50 mg/day for 4 weeks then increase the dose to 100 mg/day. However, no study has been performed on the treatment regimen. This study was conducted in order to assess the efficacy of diacerein according to the recommended regimen.

Objective : To assess the efficacy and safety of diacerein in reducing pain and functional impairment in patients with painful tibiofemoral osteoarthritis of the knee over a six-month period.

Design : Prospective study

Setting : Orthopedics Clinic, King Chulalongkorn Memorial Hospital.

Methods : Thirty patients between 50 and 65 years old with painful knee osteoarthritis (grade I to III severity on Kellgren - Lawrence radiological scale) were recruited into the study. After a 1-week NSAIDs washout period, the subjects received diacerein 50 mg/day for 1 month then increased to 100 mg/day until the end of the study. No other OA and/or pain-killer medication was allowed during the study except ibuprofen at the maximum dose of 1,600 mg/day when pain was unbearable; and, the number of tablets taken per day was recorded. The efficacy parameters were pain on walking (VAS), Lequesne index for function, intake of ibuprofen and overall efficacy were evaluated by the investigators and patients. These parameters were assessed at baseline (Day 0), Day 28, 56, 84, and 168. Routine hematology, urinalysis and clinical chemistry examinations were carried out at baseline and the end of study. The occurrence of adverse event was recorded at each visit.

Results : There was a significant reduction of pain from baseline (mean value: 59.9 mm VAS) to the last visit (mean value: 27.7 mm VAS), (p <0.001). The Lequesne index also showed a significant decrease from a baseline value of 12.5 to 5.8 on Day 168 (p <0.001). At the end of the study, about 80% of the subjects and investigators evaluated treatment efficacy as moderate to very effective. There was significant decrease in ibuprofen consumption from 678.7 mg/day at baseline to 207.6 mg/day at the end of the study. Three mild to moderate severity adverse events related to diacerein were observed which were flatulence, GI upset and diarrhea. There were no variations in the laboratory parameters measured.

Conclusion : The results of this study exhibited efficacy and safety of diacerein in the recommended regimen in the treatment of knee osteoarthritis over a six-month period.