The patent history for ciprofloxacin makes reference to a 1982 European Patent (patent number 0049355), as well a German patent dated Jan 21, 1986. Bayer introduced ciprofloxacin in 1987 and was later approved by the U.S. FDA on October 22, 1987 for use in the United States to treat specific bacterial infections. In 1991, the intravenous formulation was introduced. The current United States patent appears to be held by Bayer, being the assignee.[5] The United States patent was applied for in January 1987, but was not approved until 1996 according to the patent history.

In 2004 ciprofloxacin and levofloxacin together commanded 65% ($3.3 billion) of the global sales of the fluoroquinolone class.[6] The first nine months of 2008 sales for Ciprofloxacin were $242 million, as compared to $324 million for Bayer aspirin.[7] Ciprofloxacin has proven to be a blockbuster drug for Bayer A. G., generating billions of dollars in additional revenue. "In 1999, Cipro was the eleventh most prescribed drug in the United States based on new prescriptions, and ranked twentieth in total United States sales. In 1999, Bayer's gross sales of Cipro in the United States were approximately $1.04 billion."[8] The sale of ciprofloxacin increased dramatically following the anthrax scare of 2001. On October 24, 2002 the Bush Administration (2001–2009) announced a deal between the government and Bayer Pharmaceuticals to purchase 100 million tablets of ciprofloxacin at a reduced price of $0.95 per pill. A full course of ciprofloxacin for postexposure prophylaxis (60 days) resulting from this arrangement costs the government $204 per person treated, compared with $12 per person treated with doxycycline, the drug normally used to treat anthrax, a difference of $192.[9]

    * Generic equivalents:

On October 24, 2001, The Prescription Access Litigation (PAL), filed suit to dissolve an agreement between Bayer, Barr Laboratories, and two other generic drug companies that it claimed was blocking access to adequate supplies and cheaper, generic versions of ciprofloxacin. The plaintiffs charged that Bayer Corporation, a unit of Bayer AG, had unlawfully paid three of its competitors—Barr Laboratories, Rugby, and Hoechst-Marion Roussel—a total of $200 million to prevent cheaper, generic versions of ciprofloxacin being brought to the market, as well as manipulating the price and supply of ciprofloxacin. Numerous other consumer advocacy groups joined this lawsuit. On October 15, 2008, five years after Bayer’s patent had expired, the United States District Court for the Eastern District of New York granted Bayer’s and the generic defendants’ motion for summary judgment, holding that any anti-competitive effects caused by the settlement agreements between Bayer and the generic defendants were within the exclusionary zone of the patent, and thus could not be redressed by federal antitrust law,[10] in effect upholding Bayer’s agreement to pay Barr Laboratories, Rugby, and Hoechst-Marion Roussel a total of $200 million to prevent the marketing a generic equivalent of ciprofloxacin.