A double-blind randomized controlled trial appraising the symptom-modifying effects of colchicine on osteoarthritis of the knee.

OBJECTIVES Osteoarthritis (OA) is the most common articular disease. Common OA treatments are either not effective or associated with side effects. Calcium-containing crystals are quite common in primary OA and they worsen or may cause OA through induction of inflammation by neutrophils. Colchicine inhibits urate-crystal and calcium-pyrophosphate (CPP) crystal induced inflammation and elastase, a matrix-metalloproteinase (MMP) that play a pivotal role in degenerative joint processes. Hence, it was hypothesized that it may have symptom-modifying effects on OA. METHODS Sixty-one postmenopausal patients with primary knee OA were enrolled. None of them had joint involvement atypical for OA or evidences of chondrocalcinosis in radiographic studies suggesting the presence of calcium-pyrophosphatedeposition-disease (CPPD). Participants were allocated to two groups receiving 0.5mg colchicines BID or placebo. Both groups received common OA treatments. Acetaminophen less than 2gr/day was used as rescue-analgesic. The efficacy end points were: patients' global assessment and physician's global assessment, recorded on a VAS (visual analogue scale). Statistical analysis was performed 3 months later. RESULTS Thirty-one patients were assigned to the colchicine group. Fifty-eight patients were present for the last survey. Only 1 patient in colchicine group encountered adverse effect of colchicine without significant difference between the two groups. Acetaminophen consumption was significantly less in the colchicine (879.3±369.7) compared to placebo group (1620.7±393.1, p=0.000). Improvement rate at the end of 3 months was significantly higher in the colchicine group for both patients' global assessment and physician's global assessment measures compared to placebo group, (11.14±4.06 vs. 3.14±2.18, p=0.000) and (9.83±3.799 vs. 3.72±3.35, p=0.000), respectively. CONCLUSIONS The efficacy and safety of colchicine for pain reduction in OA was affirmed by our double-blind randomised controlled trial.