Use of mequitazine enantiomer (s) for the preparation of a medicinal product while limiting genomic toxicity

The present invention relates to the use of a mixture of enantiomers of 10- (1-azabicyclo [2.2.2] oct-3-yl-methyl) -10H-phenothiazine (mequitazine) and / or at least one of its metabolites, as well as their pharmaceutically acceptable salts, said mixture being enriched in the enantiomer of absolute configuration (S), for the preparation of an antihistamine drug intended to prevent or treat allergic conditions, while limiting the risks of cellular toxicity , including tissue and / or organic toxicity.