01713nas a2200253   4500000000100000008004100001260001300042653001200055653001200067653002200079653003000101653001100131653001200142653000900154653002500163653001300188100001500201700002100216245010300237300001100340490000800351520108600359022001401445       1989                            d  c1989 Feb10aAnimals10aDapsone10aDrug Interactions10aDrug Therapy, Combination10aFemale10aleprosy10aMice10aMycobacterium leprae10aRifampin1 aMillan J P1 aMoulia-Pelat J P00aAntagonism between dapsone and rifampicin in experimental Mycobacterium leprae infections in mice.  a143-500 v1403 a<p>In experimental infections of normal mice with Mycobacterium leprae, the bactericidal activity of four consecutive weekly doses of rifampicin (RMP) was suppressed when this treatment was preceded, for one month, by daily administration of dapsone (DDS), and then the latter. Up until now, it has been impossible to detect this antagonism between the action of RMP and DDS, since all studies involved the simultaneous administration of these two drugs, and such a phenomenon would therefore have been masked by the rapid and potent action of RMP. Previous clinical observations suggest that such a delayed antagonistic effect may also occur in humans. The demonstration of this antagonism between RMP and DDS raises the problem of the long-term efficacy of therapeutic regimens currently used in leprosy and that of the role of DDS in induction of bacillary persistence. It is suggested that this particular methodology, the delayed combination of RMP with a less active drug, should be applied to the study of other drug combinations recommended in the treatment of leprosy.</p>  a0923-2508