Dapsone alone compared with dapsone plus rifampicin in short-term therapy of lepromatous leprosy

Abstract

Previously untreated lepromatous leprosy patients were randomly allocated to treatment with either 100 mg dapsone daily or 100 mg dapsone and 600 mg rifampicin daily for 6 months. Patients receiving rifampicin improved more rapidly, but by 6 months the regimens were equivalent. There was no difference in the incidence, severity, and time of onset of erythema nodosum leprosum (ENL) in the 2 groups. Skin smears and histological sections and mouse foot-pad inoculation of biopsy specimens from skin, peripheral nerve, skeletal muscle and dartos muscle demonstrated more rapid killing of Mycobacterium leprae in those on combination chemotherapy. In the patients treated only with dapsone, viable M. leprae were generally found after 3 months of therapy, and frequently even at 6 months. Even on the combined regimens, viable M. leprae were commonly detected at 3 months, but only occasionally at 6 months.