<prompt> Clostridium difficile infection risk increases on use ofCiprofloxacinMetronidazoleVancomycinTeicoplanin  <response>: Ciprofloxacin increases risk of C.difficile enterocolitis.Metronidazole, vancomycin, teicoplanin are effective agaist C. difficile in cases of pseudomembranous colitis.Ref: Bailey and Love 27e pg: 56 