Efficacy of azathioprine in the treatment of chronic active Crohn's disease: prospective one-year follow-up study. German Imurek Study Group.

Azathioprine has been found effective in chronic active Crohn's disease. The aim of this open uncontrolled trial was an efficacy analysis in hospitals and private practices versus results of controlled trials. 89 patients with active Crohn's disease (CDAI > 150) were included in a multicenter trial of azathioprine therapy during one year. Follow-up evaluations were scheduled at three, six and twelve months and included self-assessment as well as physicians assessment of disease activity using CDAI and laboratory parameters. 65 patients (73%) completed the study per protocol until twelve months. At the end of the trial 75% of patients were in remission (CDAI < 150), 22% were ameliorated and two patients (3%) deteriorated. Corticosteroid dose was dropped from 0.46 mg/kg bw to 0.18 mg/kg bw during the study. Adverse events, primarily allergy, nausea and hyperlipasemia were frequent (21%), but only two patients had to be withdrawn from the trial. Everyday use of azathioprine for the treatment of chronic active Crohn's disease in hospital and private practice is equally effective compared to results of previous controlled trials. High doses of steroids at the beginning of azathioprine therapy may be associated with higher remission rates at one year.