Effective maintenance of inflammatory bowel disease remission by azathioprine does not require concurrent 5-aminosalicylate therapy.
OBJECTIVE
To assess the effect of 5-aminosalicylate treatment in conjunction with azathioprine on remission maintenance in inflammatory bowel disease patients.


METHODS
This retrospective study was based on a total of 186 inflammatory bowel disease patients (104 with Crohn's disease; 82 with ulcerative colitis), who were stable on azathioprine for a minimum of 6 months. The median duration of follow-up was 4.3 years (range 0.6-15.5 years). Relapse rates per year of follow-up were compared in an azathioprine + 5-aminosalicylate group (n = 103) and an azathioprine alone group (n = 83); survival curves for cumulative remission rates were compared by log-rank test. Discontinuation of azathioprine in both groups was also recorded, as was the incidence of malignancy.


RESULTS
In ulcerative colitis patients (n = 82), mean relapse rates for the azathioprine + 5-aminosalicylate group were 0.21/year compared with 0.19/year for the azathioprine alone group (P = not significant). In Crohn's disease patients (n = 104), mean relapse rates for the azathioprine + 5-aminosalicylate group were 0.27/year compared with 0.3/year for the azathioprine alone group (P = not significant). The cumulative remission percentage (determined from time to first relapse) was used in Kaplan-Meier survival analysis and showed no difference between the azathioprine + 5-aminosalicylate group and the azathioprine alone group by log-rank analysis, for ulcerative colitis and Crohn's disease as well as for all inflammatory bowel disease patients. Concurrent use of 5-aminosalicylates was no more frequent in patients who discontinued azathioprine due to adverse events. The only malignancy recorded was Waldenström's macroglobulinaemia after 7 years of azathioprine therapy.


CONCLUSIONS
Concurrent use of 5-aminosalicylate drugs did not reduce the relapse rates of inflammatory bowel disease patients who were established on azathioprine therapy. The use of 5-aminosalicylate drugs did not lead to any increase in discontinuation of azathioprine due to adverse events.
Campbell
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Gastrointestinal Unit, Department of Medical Sciences, University of Edinburgh, Western General Hospital, Edinburgh, UK. simoncampbell@hotmail.com
Ghosh
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D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001379:Azathioprine / Q000008:administration & dosage*; D003093:Colitis, Ulcerative / Q000188:drug therapy; D003424:Crohn Disease / Q000188:drug therapy; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D008297:Male; D019804:Mesalamine / Q000008:administration & dosage*; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies
D019804:Mesalamine; D001379:Azathioprine