To evaluate the optimum dose of olsalazine for maintaining remission i
n ulcerative colitis, 198 patients in remission for more than three mo
nths were randomly assigned to receive 0.5 g, 1.0 g, or 2.0 g/day for
12 months. A dose-ranging effect was detected in the per protocol anal
ysis, with remission rates of 60% (0.5 g), 70% (1.0 g), and 78% (2.0 g
) (p=0.03, trend in proportions). The higher dose was most effective i
n patients with proctitis (90% remission on 2 g/day, p=0.03) or those
in remission for less than 12 months before the trial (88% remission o
n 2 g/day, p=0.0006). There was little dose-ranging effect in patients
with extensive colitis or those in remission for more than 12 months.
Diarrhoea necessitated treatment withdrawal in 12%. The optimal dose
of olsalazine for maintaining remission in ulcerative colitis is 1 g/d
ay. For patients with proctitis or recent relapse, 2 g/day may be pref
erable, although the dose seems to be less important in patients with
more extensive disease or those in long term remission.