Fixed-duration therapy (FDT) in multibacillary leprosy; efficacy and complications.

The World Health Organization (WHO) recommended a multidrug therapy (MDT) regimen for multibacillary (MB) leprosy patients in 1982 which was to be administered for a minimum period of 2 years or until a skin smear was negative for acid-fast bacilli, whichever was later. This regimen contains rifampin, dapsone and clofazimine. A single dose of rifampin was shown to effect a high degree of bacterial killing (99.9%). The combined therapy administered for 2 years may be adequate to bring about "total" bacterial killing and to prevent the emergence of drug resistance and persisters. In this study, 360 smear-positive and previously untreated MB leprosy patients were treated with WHO/MDT for 2 years; 22.8% of these MB patients developed lepra reaction during therapy and 10.7% during surveillance. The bacterial index continued to decline even after termination of fixed-duration therapy. None of these patients relapsed during 886 person-years of surveillance.