Specific interaction studies have not been performed. In patients, who are concomitantly treated with azathioprine, 6-mercaptopurine or thioguanine, a possible increase in the myelosuppressive effects of azathioprine, 6-mercaptopurine or thioguanine should be taken into account. There is weak evidence that mesalazine might decrease the anticoagulant effect of warfarin.