Background: The role of azathioprine (AZA) in the treatment of active Crohn's disease (CD) is still controversial. This study examined whether AZA combined with standard prednisolone therapy improved the therapeutic outcome compared with monotherapy with prednisolone.
Methods: Forty-two patients with a Crohn's Disease Activity Index (CDAI) of > 150 were randomized into two groups. Both received 60 mg of prednisolone daily in a tapering regimen to a maintenance dose of 10 mg. In addition, group 1 received 2.5 mg AZA/kg body wt and group 2 received a placebo over the whole study period of 4 months.
Results: At the end of the trial, 16 of 21 patients (76%) in group 1 were in remission (CDAI < 150), compared with 8 of 21 (38%) in group 2 (P = 0.03). The CDAI in group 1 dropped from 290 +/- 97 (SD) to 72 +/- 84 and from 285 +/- 110 to 155 +/- 105 in group 2. The differences between activity indices in groups 1 and 2 became statistically significant after 8 weeks. The average prednisolone dose per day was 20.9 mg in group 1 and 26.7 mg in group 2 (P = 0.02). No major side effects were observed in this study.
Conclusion: The combination of prednisolone and AZA was superior to the treatment with prednisolone alone in active CD. Patients receiving AZA showed remission more frequently, more quickly, and with lower doses of prednisolone.