A placebo controlled, crossover study of azathioprine in Reiter's syndrome

Eight patients with intractable Reiter's disease were entered into a double blind, placebo controlled, crossover study of azathioprine versus placebo--each patient serving as his own control. Drug therapy was administered for 16 weeks, patients receiving azathioprine (eight weeks) or placebo (eight weeks) in random order. Azathioprine was given as 1 mg/kg body weight for the first month and 2 mg/kg body weight for the second month. Six individuals completed both arms of the crossover. One withdrew because of nausea during the first week (azathioprine), and a second subject withdrew at four weeks because of lack of efficacy (placebo). At the end of the 16 weeks five out of six preferred azathioprine and one placebo. The mean unweighted joint score decreased from 19.8 to 2.7 during the azathioprine medication but increased from 13.4 to 19.9 during the placebo period. Patients were unable to reduce their analgesic or non-steroidal anti-inflammatory drug requirements during the placebo period, but four out of six were able to do so during azathioprine therapy. There were no drug related laboratory abnormalities. The data suggest that azathioprine may work rapidly in Reiter's disease. If these essentially anecdotal findings of efficacy are confirmed, long term toxicity may not be an over-riding factor since for some patients therapy can be rapidly tapered at eight weeks--either because of adequate improvement or failure to respond.