List of products in the National Drug Code with proprietary name . Tinidazole is an antibiotic that is used to treat certain types of vaginal infections (bacterial vaginosis, trichomoniasis). It is also used to treat certain types of parasite infections (giardiasis, amebiasis). It works by stopping the growth of certain bacteria and parasites. This antibiotic treats only certain bacterial and parasitic 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.