GENOTOXIC EFFECTS OF METRONIDAZOLE

Metronidazole (MTZ) is an effective agent used in the treatment of par asitic infections. Its genotoxic effects have been shown in a variety of prokaryotic systems; however, negative results have been reported i n human in vivo studies. Due to its wide spread use, a study was perfo rmed to evaluate the chromosomal aberration frequencies in peripheral blood lymphocyte cultures from 10 individuals, before and after metron idazole treatment. A significant increase in the percentage of cells w ith chromatid and isochromatid breaks was observed after metronidazole treatment (1500 mg per day for 10 days). The percentages of cells wit h aberrations did not correlate with the levels of MTZ found in plasma . Individual variability was observed with respect to both the inducti on of aberrations and the concentration of MTZ in plasma. They could r epresent differences at the metabolic level, since metronidazole is kn own to be biotransformed by a polymorphic P450 cytochrome, and its met abolites have shown mutagenic activity.