Drug Therapy for Inflammatory Bowel Disease

Pharmacologic agents used for the treatment of inflammatory bowel disease (IBD) are similar for both ulcerative colitis (UC) and Crohn disease, with two major differences. Rectally instilled topical agents are effective in UC, but usually not in Crohn disease, and certainly not in Crohn ileitis. Nutritional therapy, such as the use of elemental and polymeric diets for the induction of remission, has been effective in Crohn disease, but not in UC. With these differences in mind, most drugs can be used for patients with UC or Crohn disease. The clinician's experience in the use of medications facilitates successful management. Importantly, US Food and Drug Administration (FDA) approval may apply only to some uses of these drugs, but most practitioners use the drugs based on the literature.

Management of UC tends to vary with the severity and extent of illness; active disease is treated more vigorously than inactive disease ( Box 97.1 ). Inactive clinical symptomatic disease may reflect complete remission, with no evidence of a pathologic condition or with a low-grade, chronic condition. In either case, maintenance therapy is recommended.

Depending on patient tolerance and physician preference, topical therapy in the form of enemas or suppositories is often effective for acute and maintenance therapy. Some patients cannot tolerate topical therapy, and oral medications are necessary. When severe or fulminant disease progresses, intravenous (IV) therapy is necessary. Nutrition therapy has no role in patients with UC other than to maintain adequate energy and nutrient intakes.

The same medications in UC therapy are used for patients with Crohn disease, with some variations ( Box 97.2 ). The increased incidence of perianal disease requires different approaches, and the effectiveness of infliximab has been more dramatic and is used earlier in Crohn disease. In addition, complete bowel rest and elemental or polymeric liquid diets have been effective in inducing remission when patients or clinicians do not want to use corticosteroid therapy. Although nutritional therapy is slower, significant studies have shown that it works.