Ciprofloxacin is a fluoroquinolone, a broad-spectrum antibiotic, including gram-negative and gram-positive bacteria, as well as the so-called atypical pathogens (chlamydia, mycoplasmas) and partly also anaerobic bacteria. Ciprofloxacin is used to treat various types of bacterial infections. Therefore, ciprofloxacin is used to treat people who have been exposed to anthrax or certain types of plague.