In vitro activity of epiroprim, a dihydrofolate reductase inhibitor, singly and in combination with brodimoprim and dapsone, against Mycobacterium leprae.

The antimicrobial effects of a new dihydrofolate reductase inhibitor, epiroprim, alone and in combination with dapsone and brodimoprim against Mycobacterium leprae were evaluated in vitro in cell-free culture system. Two biochemical parameters were used to measure metabolic activity (and growth) of the organism. The minimal inhibitory activity of epiroprim against M. leprae was 10 mg/l and the action was bactericidal. When combined with dapsone, epiroprim exhibited a strong synergism; on the other hand, combination of epiroprim and brodimoprim provided only additive effects. The results suggest that epiroprim can be a component in multidrug therapy regimen in leprosy.