Rifalazil (also known as KRM-1648 and AMI-1648) is an antibiotic. Rifalazil kills bacterial cells by blocking off the β-subunit in RNA polymerase. Rifalazil is used as treatments for many different diseases. Of the most common are Chlamydia infection, Clostridium difficile associated diarrhea (CDAD), and tuberculosis (TB). Using rifalazil and the effects that coincide with taking rifalazil for treating a bacterial disease vary from person to person, as does any drug put into the human body. Food interactions and genetic variation are a few causes for the variation in side effects from the use of rifalazil. Its development was terminated in 2013 due to severe side effects.