EFFECTS OF CETIRIZINE DIHYDROCHLORIDE ON HUMAN-LYMPHOCYTES IN-VITRO -MICRONUCLEUS INDUCTION - EVALUATION OF CLASTOGENIC AND ANEUGENIC POTENTIAL USING CREST AND FISH ASSAYS

mCetirizine dihydrocloride, a widely administered antiallergic drug wi th the amine piperazine in its molecule, was studied as to its ability to cause micronucleus formation in human lymphocyte cultures treated in vitro. Peripheral lymphocytes from four different donors mere cultu red and treated with different concentrations of the compound. Cetiriz ine dihydrocloride was shown to induce enhanced micronucleus frequency in a dose-dependent manner, although lymphocytes from the different d onors showed different susceptibilities to the compound. The content o f induced micronuclei was investigated in one of the four donors by tw o independent assays, CREST (the application of antikinetochore antibo dies) and FISH (fluorescence in situ hybridization) on cytochalasin B- formed binucleated cells, It was shown that the induced micronuclei re sulted from breakage events as well as chromosome loss, thus character izing cetirizine dihydrocloride as both clastogen and aneugen, Since o ur results were derived only from in vitro experiments, we believe tha t an extensive in vivo study is necessary before drawing conclusions a s to the effects of cetirizine dihydrochloride in patients.