Effectiveness of pefloxacin in the treatment of lepromatous leprosy

As a first clinical trial of a fluoroquinolone derivative in leprosy, ten previously untreated lepromatous leprosy patients, about two fifths of them with primary dapsone resistance but all susceptible to rifampin, were treated with pefloxacin 400 mg twice daily for 6 months. Definite clinical improvement was observed in all ten patients as early as 2 months after beginning treatment, and the morphological index was also drastically decreased to the baseline during the same period. The rapid bactericidal effects, as measured by serial mouse foot-pad inoculations, were demonstrated to the extent that about 99% of the bacilli were killed during the first 2 months of treatment. However, the bacterial load, in terms of the bacterial index and the number of acid-fast bacilli per mg of tissue, of the patients was only moderately reduced. The side effects were mild, and the patients tolerated the treatment well.