The invention relates to compounds and pharmaceutical compositions useful in combination with tetracyclines in the treatment of bacterial infections caused by Gram-positive and Gram-negative pathogens, with particular efficacy in tetracycline resistant strains. These compounds specifically bind to TetR and therefore prevent the transcriptional activation of tet resistance genes. The compounds have a potentiating effect on the activity of members of the tetracycline family, in particular of tetracycline, minocycline, doxycycline and tigecycline, in the treatment of tetracycline susceptible, intermediate and tetracycline resistant pathogens.
