List of products in the National Drug Code with proprietary name . This medication is used alone or with another medication to help prevent a certain serious infection (Mycobacterium avium complex-MAC). Rifabutin is known as a rifamycin antibiotic. It works by stopping the growth of bacteria. This antibiotic treats and prevents only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.