Ciprofloxacin (INN) is a synthetic chemotherapeutic agent used to treat severe and life threatening bacterial infections. Ciprofloxacin is commonly referred to as a fluoroquinolone (or quinolone) drug and is a member of the fluoroquinolone class of antibacterials. Ciprofloxacin is marketed worldwide; with well over three hundred different brand names. Ciprofloxacin is marketed in the United States, Canada and the UK as: Ciloxan, Cipro, Cipro XR, Cipro XL Ciproxin and most recently, Proquin (Synonyms: Ciprofloxacin Hydrochloride). In Mexico it is available over the counter and marketed under the names Ciproflox or Ciprofloxacino. Additionally Ciprofloxacin is available as a generic drug under a variety of different brand names and is also available for limited use in veterinary medicine.

Ciprofloxacin was first patented in 1983 by Bayer A.G. and subsequently approved by the U.S. Food and Drug Administration (FDA) for use in the United States in 1987 to treat severe and life threatening bacterial infections.

The licensed uses for ciprofloxacin in the United States are quite limited as ciprofloxacin is to be considered a drug of last resort when all other antibiotics have failed. These consist of ten approved uses in the adult population and two approved uses in the pediatric population, as well as a variety of veterinary uses (as documented within the package inserts). Any other use is to be considered off label since it has not been approved by the FDA. Ciprofloxacin interacts with a number of other drugs, a number of herbal and natural supplements, and certain thyroid medications