Minimal inhibitory dosage of rifampicin in intermittent treatment of Mycobacterium leprae infection in mice.

The total minimal inhibitory dose of rifampicin determined in the experimental mouse model, was found to be 10 mg/kg body weight, administered once a week for 6 weeks or once every 2 weeks for 12 weeks. From these and other results it is suggested that administration of RMP in human treatment can be reduced to a total amount of 7.2 either as a 600 mg dose once a week for 12 weeks or as a 900 mg dose once a week for 8 weeks. At present these regimens can only be used as an introductory treatment for multibacillary cases and are still too expensive for developing countries, but their efficacy should be evaluated in the field as sole treatments in tuberculoid cases, since they could signify a substantial economy for the management of the majority of leprosy infections.