Oral interleukin-1β blocker makes no difference in knee osteoarthritis

Treatment with the oral interleukin-1β blocker diacerein appears minimally beneficial for reducing pain in patients with knee osteoarthritis (OA), as shown in a study.

The multicentre, randomized, double-blind study included 262 patients (mean age 54.9 years, 56.1 percent female) with clinical knee OA, substantial knee pain, and effusion-synovitis on imaging. These patients were randomly assigned to receive either diacerein at 50 mg or identical placebo. Treatment was administered orally, once daily for the first 2 weeks, then increased to twice-daily dosing until 24 weeks if tolerated.

The primary outcome of change in knee pain over 24 weeks was evaluated using the visual analogue scale (range 0–100 mm; minimal clinically important improvement 15).

A total of 231 patients (88.2 percent) completed the study. Over 24 weeks of treatment, the improvements observed in knee pain did not significantly differ between the diacerein and placebo groups (−19.9 vs −18.6 mm, respectively; mean difference, −1.3 mm, 95 percent confidence interval, −9.8 to 7.3).

In terms of safety, gastrointestinal symptoms occurred frequently, reported in 41.7 percent of patients in the diacerein group and in 25.4 percent in the placebo group. Diarrhoea was the most common gastrointestinal symptom (38.6 percent vs 22.3 percent). In the diacerein group, 9.8 percent of patients reported a change in urine colour.

The findings do not support diacerein for treating knee pain in this population.