Zyvox New Drug to Attack Resistant Germs

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F.D.A. Approves New Drug to Attack Resistant GermsBy SHERYL GAY STOLBERGWASHINGTON, April 18 -- The Food and Drug Administration today approved a drug that is considered an important new weapon in the fight against antibiotic-resistant germs. The drug, Zyvox, is the first in a new family of antibiotics, and the first medicine in more than 40 years to treat a potentially lethal strain of staphylococcus now on the rise.The approval of Zyvox, which is made by the Pharmacia Corporation of Peapack, N.J., comes as doctors grow concerned about so-called superbugs, including some that even resist vancomycin, long regarded as the antibiotic of last resort for a range of disease-causing germs.Zyvox, which goes by the generic name linezolid, is not a panacea. It only works against certain disease-causing bacteria, and in studies of patients with the toughest infections -- those that cannot be treated with vancomycin -- it cured only two-thirds of the cases.Even so, infectious-disease experts said the drug could help thousands, perhaps tens of thousands, of people each year, especially those in hospitals and nursing homes, where microbes quickly attack the elderly, people with weak immune systems and other vulnerable patients."It is a major advance to have this option," said Dr. Eliopolous, an infectious disease expert at Beth Israel Medical Center in Boston. "They are hitting the market at a good time, when we are starting to see more of these bacterial infections."The F.D.A. approved Zyvox as a treatment for several types of illnesses. Most important among them, experts said, are the skin and bloodstream infections and pneumonia caused by a deadly bacteria, enterococcus faecium, that does not succumb to vancomycin.This strain -- known by the acronym VREF, for vancomycin-resistant enterococcus faecium -- first emerged in 1989, then spread rapidly. By 1997, according to the Centers for Disease Control and Prevention in Atlanta, half of all enterococcus faecium germs could not be attacked by vancomycin. About 14,000 patients a year get sick from the germ, an agency official said. Last year, another antibiotic, Synercid, was approved to treat VREF. But Synercid, which is made by Rhône-Poulenc Rorer, is given by injection only, while Zyvox can be administered intravenously or in pill form. Thus, doctors can prescribe it in the hospital and send patients home to continue treatment without intravenous equipment."The fact that it is approved for oral use is important," said Dr. M. Bell, an expert in antibiotic resistance at the center.Referring to both Zyvox and Synercid, Dr. Bell said, "We are delighted to see these new drugs coming out of the pipeline and into clinical use." In addition to drug-resistant enterococcus bacteria, scientists have grown concerned about the rise of another microbe that causes skin and bloodstream infections and pneumonia, staphylococcus aureas, that has outwitted most antibiotics.

Zyvox is a member of an new family of medications, the oxazolidine class; it works by blocking the formation of proteins that enable bacteria to spread inside the body. Other antibiotics, including Synercid, attack at different points in the life cycle of the bacteria.That does not mean bacteria cannot become resistant to Zyvox; Dr. Chikami, the drug agency official, said that during clinical testing, a few patients' vancomycin-resistant enterococcus infections also became resistant to Zyvox.As a result, government officials say doctors should use the new drug with caution. "It is likely that in time that resistance will develop," Dr. Bell said. "So we need to use these new drugs judiciously."Dr. Burt Meyers, an infectious disease expert at Mount Sinai School of Medicine in Manhattan, said there was another reason doctors should use Zyvox sparingly: its cost. Vancomycin, which he described as "the drug of choice at this time," is relatively inexpensive, costing about $14 a day, Dr. Meyers said. Zyvox, which should reach the market within a few weeks, may cost more than 10 times that. Mr. Durrant said that Pharmacia would not set a price until next week, but that Zyvox would probably cost slightly less than Synercid's rate of $180 to $250 a day.