Two steroid preparations show similar efficacy in chronic inflammatory arthritis

The intra-articular steroid preparation methylprednisolone acetate (MPA) is as effective as triamcinolone acetonide (TA) in the treatment of chronic inflammatory arthritis, according to the results of a trial.

“However, results need to be extrapolated cautiously because of the small sample size,” researchers said.

In the trial, 89 patients with rheumatoid arthritis and 11 with spondyloarthritis who presented with an acutely swollen knee joint (≥1 week, <24 weeks) were randomized to receive intra-articular knee injections with either MPA or TA (at 1:1 ratio; 80 mg, 2 mL of each). 

Assessments were conducted at three time points: 4, 12 and 24 weeks.

Primary endpoint was time to relapse (defined as return to baseline pain or swelling ≥1 week) over 24 weeks. Secondary endpoints included change in pain and swelling (using a numerical rating scale), range of movement and occurrence of adverse effects.

Analysis was performed on an intention-to-treat basis, with last observation carried forward.

Relapse over 24 weeks occurred in nine patients in each treatment arm. The mean time to relapse was comparable between the MPA and TA arms (20.8 vs 20.9 weeks, respectively; p=0.9). Three-quarters of the patients remained relapse free at 24 weeks.

Both MPA and TA produced a significant improvement in pain and swelling scores at all time points (p<0.001). The mean change in pain at 24 weeks was –4.4 with MPA and –3.9 with TA. No significant between-group difference was observed.

There were no reports of infection, hematoma or hypopigmentation. Moreover, the occurrence of joint swelling, range of movement, modified (28 joint) Disease Activity Score using 3 variables, or Health Assessment Questionnaire over 24 weeks was similar between the two treatment arms.

The findings suggest that the two of the most commonly used intra-articular steroid preparations—MPA and TA—are effective in the treatment of chronic inflammatory arthritis.