Clinical Experience with 5-Aminosalicylate Preparations in Inflammatory Bowel Disease - A Review

The efficacy of 5-ASA tablets is around 65 co 70% in patients withactive ulcerative colitis, whereas the efficacy of the rectal preparations approach 100%when the treatment is for active distal disease. When there is more extensive left sidedcolonic disease, the efficacy of 5-ASA rectal preparations is not as high, but it is stillmuch improved over that seen with oral 5-ASA preparations. There is no dataavailable for total colonic disease of either ulcerative colitis or Crohn's disease.There is no controlled maintenance data available for Crohn's disease using 5-ASApreparations and no controlled or comparison data available for rectal preparations inCrohn's disease. There are no controlled dose-response studies of 5-ASA in patientswith Crohn's disease. Thus, the most "therapeutic" dose is not known. The author'sanecdotal evidence reports char patients with Crohn's disease affecting the rectum orleft colon respond poorly to 5-ASA enemas. However. with continued use of morethan six weeks at least a 50 to 60% respone is seen. In contrast, virtually all patientswith ulcerative proctitis respond by six weeks and all are controlled by 10 to 12 weeks.When oral 5-ASA is compared with conventional oral sulfasalazine therapy, theefficacy is comparable. However, with 5-ASA the incidence of side effects is considerablylower; the number of patients discontinuing therapy is less; patient compliance isbetter, especially for the long term; dosage increase following inadequate action ismore readily possible; and bacterial activation of the drug given is not necessary