Sixty-six outpatients with active
ulcerative colitis who were intolerant of
sulfasalazine were treated in a double-blind randomized trial. They received placebo or
olsalazine sodium in daily doses of 0.75, 1.5, or 3 g. Overall, 35% of patients receiving
olsalazine improved clinically, compared to 16% of patients receiving placebo. When the
colitis activity at study entry was compared with that observed at the completion of the study period, statistically significant or nearly significant improvement was demonstrated within the combined
olsalazine group (p = 0.01) and within patient groups receiving
olsalazine at daily doses of 1.5 g (p = 0.04) and 3 g (p = 0.055). A dose-response relationship was suggested because 16%, 29%, 27%, and 50% of patients improved in the placebo and 0.75-, 1.5-, and 3-g
olsalazine groups, respectively, (p = 0.04). A similar pattern of improvement was seen when sigmoidoscopic criteria were used, although a dose-response relationship was not demonstrated. There were no differences between the treatment and placebo groups for any of the adverse effects or laboratory variables reported at baseline or during the trial period. Four patients were withdrawn because of adverse reactions: 2 developed a
skin rash while receiving
olsalazine and 2 had
diarrhea, one while on
olsalazine and the other while on placebo. The data suggest that
olsalazine is effective for the treatment of
ulcerative colitis and is well tolerated among patients intolerant to
sulfasalazine.