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Cipro (ciprofloxacin) is a drug belonging to a class of antibacterials known as fluoroquinolones. These drugs are used to treat a variety of bacterial infections. Among physicians, Cipro is one of the most popular drugs for the treatment of urinary tract infections (UTIs).

While most of Cipro's potential side effects are quite rare, some can be very serious. Specifically, Cipro has been linked to tendinitis and tendon ruptures in scores of patients worldwide. For years consumer groups and others warned of the potential risks of taking Cipro, but despite their efforts the U.S. Food and Drug Administration (FDA) failed to require the manufacturers of Cipro and other drugs in its class to take serious action. This lack of action on the part of the FDA does not, however, relieve the manufacturers of liability for harm caused by their drugs.

If you or someone you know has suffered from the side effects of Cipro or another fluoroquinolone, see a doctor immediately and consult with a personal injury lawyer who can determine whether you may be eligible for compensation.

Cipro Black Box Warning

Black box warnings are the FDA's most visible warnings of a drug's potential risks. Short of recalls, these warnings are considered the most serious action taken by the FDA. In the case of Cipro and other fluoroquinolones, this type of warning might never have been issued had it not been for the efforts of advocates outside the pharmaceutical industry.

Tendon Ruptures

The controversy surrounding Cipro and other fluoroquinolones stems from their role in hundreds if not thousands of tendon-related injuries in patients taking these drugs. One of the common tendon injuries linked to Cipro is tendon rupture, particularly ruptures of the Achilles tendon.

The Achilles tendon is a large, tough, fibrous area of connective tissue that links the calf muscles to the heel bone. Rupturing the Achilles tendon is usually very painful. Patients often report a "pop" or "snap" in the area just above the heel bone, followed by sharp pain and difficulty walking. Achilles tendon ruptures are classified as either partial or complete and typically require rehabilitation and/or surgery.

Patients who have ruptured a tendon usually experience severe pain and make their way to a doctor shortly thereafter. This is not necessarily the case among those with tendinitis and other, more minor tendon injuries and aggravations. If you have noticed swelling or tenderness near the back of your ankle or heel bone, or in other tendons, see a doctor as quickly as possible. If you believe the injury may be linked to Cipro or another fluoroquinolone, contact a personal injury lawyer.

The following is a timeline outlining this fight:

1996 - Both researchers and the FDA have been aware of Cipro's side effects for over 10 years. In 1996, consumer advocacy group Public Citizen wrote to the FDA, urging the agency to require more visible warnings for doctors and their patients. In this letter, they noted manufacturers' heavy promotion of fluoroquinolones for the purpose of treating infections, despite the fact that these drugs are considered "second-line" treatments for the vast majority of infections. Also noted were the numerous reported cases of tendon rupture in patients taking Cipro and other fluoroquinolones in the previous 18 months.


2005 - Faced with evidence of a steady increase in tendon problems associated with these drugs, in 2005 the Illinois Attorney General's office requested (unsuccessfully) that the FDA require the manufacturers of Cipro and other fluoroquinolones to add a bold "black box" warning to the drugs' packaging.

2006 - In 2006 Public Citizen and the Illinois Attorney General teamed up to petition the FDA, seeking once again to have black box warnings added to fluoroquinolones. In addition, they requested that medical guides be developed to educate doctors and patients.

2008 - In a last-ditch effort to alert consumers, in 2008 Public Citizen filed suit against the FDA. Finally, faced with mounting evidence and a lawsuit, in July 2008 the FDA notified the manufacturers of Cipro and other fluoroquinolones that henceforth a black box warning and Medical Guide would be required. The FDA reiterated the potential complications researchers and consumer groups had been warning of for years and noted which patients were at highest risk of developing these complications.

Throughout this lengthy battle the manufacturers of fluoroquinolones were aware of their products' side effects. Regardless of the FDA's role, these companies are still liable for harm caused by their drugs. If you or a loved one has been harmed as a result of taking Cipro or another fluoroquinolone, contact a personal injury attorney who can evaluate your case and help determine your chances of receiving compensation for your suffering.

Cipro Side Effects

While most side effects of Cipro are rare, the incidence of tendinitis and tendon rupture is notable. At-risk groups include patients over 60 years of age and anyone who has had a kidney, lung or heart transplant. Other potential side effects of fluoroquinolones are listed in the chart below.

Other Side Effects

Occasional Rare








Candida vaginitis

Associated colitis

Photosensitivity/phototoxicity reaction

Allergic reactions (some severe)

QTc prolongation

Hepatic failure

Peripheral neuropathy



Interstitial nephritis

Source: Source: Johns Hopkins Point of Care Information Technology Center

If you have experienced any of these symptoms, see a doctor immediately and contact a personal injury lawyer to review your case.

Cipro Lawsuits

Lawsuits against Bayer Pharmaceuticals, the manufacturer of Cipro, allege that the company failed to properly warn consumers of the risk of tendon rupture and other side effects of Cipro.


Ciprofloxacin (Cipro) belongs to a class of drugs known as fluoroquinolones, which are one of the most commonly prescribed classes of antibacterial drugs. Other fluoroquinolones include levofloxacin (Levaquin), ofloxacin, norfloxacin and others. These and other antibacterial drugs are distinguished from antibiotics in that they derive from bacteria and molds. For some physicians, fluoroquinolones are the drug class of choice for urinary tract infections (UTIs).

Groups at highest risk of developing side effects from taking fluoroquinolones include those over 60 years of age and people who have had heart, lung or kidney transplants.

As outlined above, the risks have been known for more than a decade, yet Bayer and other manufacturers of fluoroquinolones did not voluntarily develop medical guides or include the most visible form of warnings on the packaging of their products. Although this may constitute negligence, the defective product claims and pharmaceutical liability laws that govern defective drug cases do not require plaintiffs to show that the manufacturers and/or distributors of these drugs acted negligently. Under these laws, their role in the production and distribution of the drugs is often enough to hold them liable, regardless of whether there is any further drug mistake.

Hundreds if not thousands of people have suffered as a consequence of taking Cipro and other fluoroquinolones. If you or someone you know has experienced tendon-related problems or any of the other side effects listed in this article, contact a personal injury attorney who can assess your case and help you determine whether you may be eligible for compensation for your suffering.