To test the hypothesis that colchicine is an effective treatment of psoriatic arthritis.
Twenty five patients with psoriatic arthritis were entered into a two centre, double blind, crossover study of 23 weeks' duration comparing the therapeutic effect of colchicine (0.6-1.8 mg/day) with placebo.
No significant difference was noted between colchicine or placebo treatment for the primary outcome measure (Lansbury joint count) or any of the seven secondary outcome measures. No change in the psoriasis was noted during active or placebo treatment. Adverse clinical effects were reported more often during treatment with colchicine (14 patients) than with the placebo (four patients), resulting in the early withdrawal of three patients receiving colchicine from the trial. Increased creatine kinase values, without weakness, occurred during treatment with colchicine (five patients) and placebo (four patients).
In conclusion, our study did not provide evidence that colchicine is of therapeutic value in the treatment of psoriatic arthritis.