Infliximab in the treatment of Crohn's disease: a user's guide for clinicians.

Induction therapy with infliximab is indicated for treatment of signs and symptoms, and induction and maintenance of remission in patients with moderate to severely active inflammatory Crohn's disease with an inadequate response to conventional therapy, and for reduction in the number of draining fistulas in patients with fistulizing Crohn's disease. Emerging indications for infliximab therapy in patients with Crohn's disease include maintenance of fistula improvement (reduction in the number of draining perianal or enterocutaneous fistulas) and complete fistula response (no draining fistulas) in patients with fistulizing Crohn's disease, steroid sparing in steroid-treated patients, early use in hospitalized patients who have not failed conventional medical therapy where there is either a severe clinical presentation or a rapid onset of action is desired, and in a variety of unusual and extra-intestinal manifestations of Crohn's disease. An infliximab dose of 5 mg/kg is recommended initally, but some patients who require maintenance dosing may benefit from increasing the infliximab dose over a range of 5-10 mg/kg. An induction regimen of 3 doses at 0, 2, and 6 weeks is the preferred dosing strategy for inducing remission. The optimal dosing interval for patients who require retreatment appears to be every 8 weeks for most patients. Concomitant immunosuppressive therapy with azathioprine, 6-mercaptopurine, or methotrexate may result in improved outcomes due to a reduction in the frequency of human anti-chimeric antibody formation, acute infusion reactions, and a reduced risk of delayed hypersensitivity-like reactions and formation of antinuclear antibodies. Pretreatment with diphenhydramine (and in selected cases of acetaminophen and, rarely, corticosteroids) is recommended in patients with a history of infusion reactions and patients at risk for delayed hypersensitivity-like reactions. Patients with evidence of active infection should not receive infliximab until the infection is adequately treated, and all patients should be screened for tuberculosis prior to initiating infliximab therapy.