Parenteral high dose methotrexate and sulfasalazine are the only two agents with well demonstrated published efficacy in psoriatic arthritis. The magnitude of the effect seen with azathioprine, etretinate, oral low dose methotrexate and perhaps colchicine suggests that they may be effective but that further multicentre clinical trials are required to establish their efficacy. Furthermore, the magnitude of the improvement observed in the placebo group strongly suggests that uncontrolled trials should not be used to guide management decisions in this condition.
Randomized, double-blind, placebo controlled trial of low-dose pulse methotrexate in psoriatic arthritis.
Thirty-seven patients with psoriatic arthritis were entered into a 12-week prospective, controlled, double-blind multicenter trial comparing placebo and oral pulse methotrexate therapy. Methotrexate was given in a dose of 2.5-5.0 mg every 12 hours in 3 consecutive doses per week. A stable background medication program with nonsteroidal antiinflammatory drugs was allowed. Methotrexate was superior to placebo only in physician assessment of arthritis activity and in improvement of the amount of skin surface area with psoriasis. A small but statistically significant rise of serum total bilirubin occurred in the methotrexate-treated patients. No patients were withdrawn from the study for adverse drug effects.