Results of a modified WHO regimen in highly bacilliferous BL/LL patients

A regimen consisting of 600 mg of rifampin once a month, 100 mg of clofazimine on alternate days, and 100 mg of dapsone daily was used in 56 untreated, highly bacillated borderline lepromatous/lepromatous (BL/LL) patients with an average bacterial index (BI) of 4.45. Treatment was continued until skin-smear negativity. After 2 years of therapy, none of the patients had become smear negative and the average BI was 2.56. There was no growth on inoculation of skin-tissue biopsies in the normal mouse foot pad after 6 months of therapy. Bacillemia was still detectable in 11/50 patients, and significant ATP levels were detected in Mycobacterium leprae from skin-tissue biopsies in 16% of the cases. After 3 years of therapy, three patients had become smear negative. The average BI was 1.30. None of the patients had detectable bacillemia, and 5% of the cases showed detectable ATP levels in M. leprae from tissue biopsies. After 4 years of therapy, 41.7% of the patients had become smear negative. The average BI was 0.66, and no ATP was detected in any of the purified bacillary suspensions. The fall in BI was accelerated, and more patients on continued treatment became negative earlier compared to those having treatment for a limited duration, as reported by others.