Probably "ciprofloxacin" (Cipro), a fluoroquinlone. Actually, the treatment for _cutaneous_ anthrax is either doxycycline (a tetracycline-like drug) or cipro for 60 days, rather than the "mere" 30 they are suggesting.
In Canada, 60 days of cipro for 2 people is $1300. 60 days of doxy for 2 people is under $200. This presumes you have _cutaneous_ anthrax. Apparently, pulmonary anthrax requires IV treatment, and it's almost too late once you have symptoms. [Apparently, public health here in Montreal has been getting a lot of such questions. In case anyone is wondering, No, there is no commercial anthrax vaccine available here in Canada either! ;-)]
