ORAL TOBRAMYCIN IN ULCERATIVE-COLITIS - EFFECT ON MAINTENANCE OF REMISSION

Oral tobramycin for 7 days has been shown to be of benefit as an adjun ct to conventional medication in acute ulcerative colitis. Eighty-one patients (40 who had received tobramycin; 41 placebo) who had been enr olled in a double-blind placebo-controlled trial of this drug in acute disease were subsequently followed to determine whether this short-te rm benefit persisted. Relapse was defined as a liquid stool frequency of three times daily with rectal bleeding. Results were analysed by th e log-rank test on Kaplan-Meier survival curves. Treatment failure was defined as a lack of response by the end of the acute trial period, o r subsequent relapse. In a second analysis, only those entering remiss ion at the end of the acute trial were considered, and followed to rel apse. Although at the start of the follow-up period significantly fewe r patients in the tobramycin group had failed (failed: tobramycin 9, p lacebo 24; not failed tobramycin 31; placebo 17; P = 0.001), the failu re-free survival curves subsequently converged and did not differ sign ificantly. After 1 and 2 years, the failure-free survival rates were 4 0 % (S.E. = 7.8 %) and 20 % (S.E. = 6.3 %) for the tobramycin group an d 24 % (S.E. = 6.7 %) and 1 2 % (S.E. = 5.1 %) for the placebo group. When only those entering remission were considered, there was no signi ficant difference in the relapse rates in the two groups. Benefit from tobramycin is therefore short-lived and may reflect short-term change s in the faecal flora.