List of the 2 NDC products with the active ingredient Benznidazole. Benznidazole is an antibiotic that is used to treat a certain parasitic infection (Chagas disease). It works by stopping the growth of a certain parasite. This antibiotic treats only Chagas disease. 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.