- The Washington Times - Wednesday, April 19, 2000

Doctors got an important new weapon in the battle against drug-resistant infections yesterday when the government approved a long-awaited drug called Zyvox, described as the world's first entirely new type of antibiotic in 35 years.

Zyvox seems to cure some infections impervious to all other antibiotics, even that longtime drug of last resort called vancomycin. Consequently, Zyvox could help prevent hundreds, perhaps even thousands, of life-threatening infections every year.

"It comes at a time when we were literally running out of antibiotics," said Dr. Robert C. Moellering Jr., physician in chief of Boston's Beth Israel-Deaconness Hospital.

Plus, it is being made in both oral and intravenous forms meaning that when hospitals discharge infected patients, they might go home with pills instead of a troublesome IV unit, said Dr. Dennis L. Stevens of the Veterans Affairs Medical Center in Boise, Idaho.

"Zyvox is just a superb drug," said Dr. Stevens, who helped test it. "It's good … to treat some pretty nasty infections with an oral drug."

But he stressed that doctors should reserve Zyvox for only the worst infections and those suspected of being antibiotic-resistant, or bacteria will quickly evolve to make Zyvox useless.

"It's my wish that Zyvox is used primarily in hospitals," not when primary care physicians just hand out a routine antibiotic prescription, he said.

The Food and Drug Administration approved Zyvox made by Peapack, N.J.-based Pharmacia Corp., yesterday for use by adults with pneumonia and skin infections, including those caused by a tough-to-treat form of staph bacteria, and with deadly infections caused by a supergerm named Enterococcus faecium.

This infamous germ frequently invades surgical wounds and causes serious abdominal, urinary tract and heart valve infections. Worse, enterococcal infections are growing increasingly impervious to antibiotics. About a quarter of enterococcal infections among intensive-care patients last year were untreatable by even vancomycin, a stunning 43 percent increase from the mid-1990s, said FDA antibiotic chief Dr. Gary Chikami.

But in a clinical trial of 145 persons with vancomycin-resistant enterococcal infections, Zyvox cured 67 percent.

In additional studies, Zyvox helped other infections as well as vancomycin or other standard treatments.

Zyvox isn't the only option for untreatable infections: The FDA last fall approved competitor Aventis' Synercid as the nation's first alternative when vancomycin fails. Synercid, an intravenous drug, is a combination of two older European antibiotics that delivers a one-two punch against bacteria.

In contrast, Zyvox is a synthetic chemical designed from scratch to fight germs at an entirely different point in their life cycle than any other medicine a true surprise attack. It stops bacteria from making protein, which in turn stops their growth so the body's immune system can step in and finish them off, Dr. Moellering said.

Known chemically as linezolid, it is the first in a long-awaited class of antibiotics called oxazolidinones.

But it's not a magic bullet. Zyvox has been used experimentally in only a few thousand people, yet doctors already have counted 15 Zyvox-resistant infections.

Nor can it fight all bacteria, only a certain type known as "gram-positive."

But gram-positive bacteria are a huge public health threat. They cause more than half of all serious infections treated in hospitals worldwide, particularly the kind caught by patients while they're in the hospital for some other problem.

Zyvox's main side effects are headache, nausea, vomiting and diarrhea, afflicting between 3 percent and 11 percent of patients, the FDA said. The oral version caused more side effects.

Also, Zyvox can cause a decrease in blood platelets, so doctors must monitor patients' blood, the FDA warned.

Zyvox patients should tell their doctors if they take over-the-counter decongestants such as those containing pseudoephedrine, or antidepressants such as Prozac, because Zyvox can interact with such drugs to raise blood pressure.

Pharmacia said Zyvox would be available within a few weeks but refused to disclose the price except to say it was expected to be a little lower than competitor Synercid, which costs $85 per intravenous vial.

Shares of Pharmacia closed down $1.13 to $53 on the New York Stock Exchange.

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