Maintenance of remission induced by medical therapy and prevention of recur
rence after intestinal resection are two of the major goals in Crohn's dise
ase treatment. Two main groups of drugs are employed in prevention of relap
se and recurrence: sulfasalazine and 5-aminosalicylic derivatives and the g
roup of azathioprine/6-mercaptopurine. Although most clinical trials on the
efficacy of sulfasalazine as maintenance therapy of Crohn's disease have g
iven negative results, it could probably be favourably used in remission ma
intenance of Crohn's colitis. Controlled studies and two reviews have-shown
that 5-aminosalicylic derivatives are effective in reducing the risk of re
lapse. Ileitis and ileocolitis respond better than colitis. These drugs are
also able to reduce the severity of lesions and of symptoms after surgery.
6-mercaptopurine and azathioprine can be used in more aggressive forms of
the disease. The efficacy of this immunosuppressive therapy is reported in
over 70% of patients and the incidence of associated side effects is accept
able, but 6-mercaptopurine and azathioprine act slowly and the long latency
period limits the usefulness of these drugs in some patients.