Evaluation of genotoxicity of clofazimine, an antileprosy drug, in mice in vivo. I. Chromosome analysis in bone marrow and spermatocytes.

Clofazimine, an antileprosy drug, was tested for its cytogenetic effect in mouse bone marrow and testis. Bone marrow metaphase analysis in adults treated directly for different periods (1, 2 and 4 weeks, 40 mg/kg/day) and with different doses (4, 20 and 40 mg/kg/day for 7 days) as well as in young animals exposed through lactation for different periods (2, 3, and 4 weeks) revealed significant increases in chromosomal aberrations over the controls. Analysis of diakinesis-metaphase I stages also exhibited a significantly elevated incidence of chromosome aberrations over controls after treatment for different periods. On the basis of the present result the drug may be considered a potential clastogen in mice.