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Evidence summaries

Azathioprine or 6-Mercaptopurine for Inducing Remission of Crohn's Disease

Azathioprine and 6-mercaptopurine appear not to be effective in inducing remission in Crohn's disease compared with placebo. Infliximab appears to be more effective than azathioprine for induction of remission. Level of evidence: "B"

A Cochrane review [Abstract] 1 included 13 RCTs (n=1211) of azathioprine and 6-mercaptopurine therapy in adult patients with Crohn's disease. There was a trend favouring azathioprine or 6-mercaptopurine but no statistically significant difference in clinical remission rates or improvement compared with placebo (table T1). A steroid sparing effect (prednisone dose less than 10 mg/day while maintaining remission) was seen with azathioprine (table T1) There was no difference in adverse events requiring withdrawal. Azathioprine was inferior to infliximab for induction of steroid-free clinical remission and mucosal healing (table T2). The combination of azathioprine and infliximab was significantly superior to infliximab alone for induction of steroid-free clinical remission (table T3). Azathioprine or 6-mercaptopurine therapy was found to be no better at inducing steroid free clinical remission compared to methotrexate and 5-aminosalicylate or sulfasalazine. There were no statistically significant differences in withdrawals due to adverse events between azathioprine or 6-mercaptopurine and methotrexate; between azathioprine or 6-mercaptopurine and 5-aminosalicylate or sulfasalazine; between azathioprine and infliximab; or between the combination of azathioprine and infliximab and infliximab.

Azathioprine (AZA) or 6-mercaptopurine (6-MP) versus placebo for induction of remission in Crohn's disease

OutcomeRelative effect(95% CI)Assumed risk - Control - PlaceboCorresponding risk - Intervention: AZA or 6-MP (95%CI)No of Participants(studies), Quality of evidence
Clinical remission1.23 (0.97 to 1.55)372 / 1000458 / 1000(361 to 577)380(5), Moderate
Clinical remission or improvement1.26 (0.98 to 1.62)359 / 1000452 / 1000(352 to 582)434(8), Moderate
Steroid sparing effect1.34 (1.02 to 1.77)457 / 1000612 / 1000(466 to 809)143(4), Moderate
Withdrawals due to adverse events1.70(0.94 to 3.08)53 / 100090 / 1000(50 to 163)510(8), Moderate

Azathioprine (AZA) versus infliximab (IFX) for induction of remission in Crohn's diseas

OutcomeRelative effect(95% CI)Assumed risk - Control - AZACorresponding risk - Intervention: IFX (95% CI)No of Participants(studies) Quality of evidence
Clinical remission0.66 (0.51 to 0.87)479 / 1000316 / 1000(244 to 417)339(1), Moderate
Clinical remission off steroids0.68 (0.51 to 0.90)444 / 1000302 / 1000(226 to 400)339(1), Moderate
Mucosal healing0.55 (0.33 to 0.94)283 / 1000156 / 1000(93 to 266)214(1), Moderate
Withdrawals due to adverse events1.47 (0.96 to 2.23)178 / 1000262 / 1000(171 to 397)324(1), Moderate

Azathioprine + infliximab (AZA+IFX) versus infliximab (IFX) for induction of remission in Crohn's disease

OutcomeRelative effect(95% CI)Assumed risk - Control: IFXCorresponding risk - Intervention: AZA + IFX (95% CI)No of Participants(studies) Quality of evidence
Clinical remission1.26 (1.03 to 1.54)479 / 1000603 / 1000(493 to 738)338(1), Moderate
Clinical remission off steroids1.23 (1.02 to 1.47)482 / 1000593 / 1000(492 to 708)383(2), Moderate
Mucosal healing1.50 (1.02 to 2.19)283 / 1000424 / 1000(289 to 620)210(1), Moderate
Withdrawals due to adverse events1.16 (0.75 to 1.80)178 / 1000206 / 1000(134 to 320)342(1), Moderate

References

  • Chande N, Townsend CM, Parker CE et al. Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease. Cochrane Database Syst Rev 2016;(10):CD000545. [PubMed]

Primary/Secondary Keywords