That's not what the article says
According to the article that Tom provided, "The generic antibiotics doxycycline and penicillin have long been approved by the Food and Drug Administration as treatments for anthrax, while the newer Cipro was approved just last year."
I think doxycycline is more widely known as Tetracycline. It shouldn't be used by young children (stains their teeth) or pregnant women but is considered effective for other people.