In response to pressure from the consumer group Public Citizen the U.S. Food and Drug Administration has added a “black box” warning to the family of antibacterial drugs called flouroquinolone. The use of Cipro, made by Bayer and Levaquin made by Ortho-McNeil may lead to tendon ruptures, a serious injury that can incapacitate patients and increase the possibility of extensive surgery. Some of the ruptures reported to the FDA occurred without warning when the patient felt a snap or pop soon after starting treatment suggesting that flouroquinolone antibiotics may be toxic to some people, the FDA said. Typically, patients felt some kind of pain or inflammation for a week or two before they suffered a tendon rupture. The link between the treatment of the antibiotics and the tendon ruptures is highly unusual and scientists still don't fully understand why it happens. The FDA further added that the risk of tendon ruptures decrease if patients stop taking the drug at the first sign of pain or swelling. Public Citizen petitioned the FDA nearly two years ago to add more effective warnings and feel the regulators took too long to act citing many injuries, “would have been prevented if patients and doctors had known a pain in the tendon is an early sign that leads to rupture,” said Sidney Wolfe, head of the consumer group. In defense, the FDA pointed out that the prescribing literature already carried clear warnings regarding the risk of tendon ruptures, but decided to emphasize the warnings because of continued reports of injuries indicated the public may not have been paying enough attention. FDA officials said they had received several hundred reports of tendon ruptures. Wolfe, of Public Citizen, said the number was 407 at the end of 2007, with another 341 reports of tendinitis. He continued to criticize the agency, saying it should also require drug makers to send individual letters to doctors about the risks. FDA officials said manufacturers could choose to send such letters on their own. The FDA’s analysis revealed that patients who are over 60, those on steroids, or patients with kidney, heart and lung transplants are at the highest risk of tendon rupture.