%A Walker LL %A Landingham RMV %A Shinnick TM %T Clarithromycin is bactericidal against strains of Mycobacterium leprae resistant and susceptible to dapsone and rifampin %0 Journal Article %D 1993 %J International Journal of Leprosy and other Mycobacterial Diseases %P 0148-916X %V 61 %N 1 %X The anti-Mycobacterium leprae activity of clarithromycin when administered alone and in combination with rifampin and dapsone in the diet was determined using the kinetic method of drug evaluation in mice. Clarithromycin when administered at a concentration of 0.1% (w/w) in the diet completely prevented growth of 2 pan-susceptible, 3 dapsone-resistant, 2 rifampin-resistant, and 2 rifampin and dapsone double resistant strains of M. leprae. A 0.03% (w/w) concentration also completely prevented growth of M. leprae in all mice infected with 2 of 7 strains tested, but in only some of the mice infected with the remaining 5 strains. No antagonistic drug interactions were observed between clarithromycin and dapsone or rifampin. The addition of clarithromycin to the currently recommended multidrug regimen should improve the rate of killing of M. leprae and help to prevent the growth of dapsone-resistant and rifampin-resistant strains.