Relapses after a single dose of rifampin in skin-smear negative multibacillary patients after dapsone monotherapy.

Between 1982 and 1985, a single 1500 mg dose of rifampin (RMP) was given to 136 multibacillary leprosy patients who had become clinically inactive and skin-smear negative after various durations of dapsone monotherapy, and then antileprosy chemotherapy was totally stopped. By the end of June 1992, 15 relapses were detected among these patients. The overall relapse rate was 11%; the relapse rate per 100 patient-years was 2.1%, which was the highest among those published to date; the cumulative risk of relapse at year 7 of follow up was 8.8%. All of these figures indicate that the relapse rate among this group was at least the same as in other studies where patients received dapsone monotherapy only. Therefore, the administration of a single large dose of RMP could neither prevent relapse nor reduce its rate among multibacillary patients who had already become clinically and skin-smear negative after dapsone monotherapy.