Super-germ alert: how to avoid antibiotic misuse and overuse.(Your Health)

The long-simmering problem of antibiotic resistance seems to be nearing the boiling point. More than two-thirds of the bacterial infections acquired in U.S. hospitals and about half of the common bacterial infections in outpatients do not respond to at least one of the antibiotics that used to work. For the first time, there are now five types of bacteria with strains resistant to all available antibiotics.

Many factors contribute to the looming crisis, including the use of antibiotics in animals and agricultural products, and possibly the use of antibacterial cleaners. But the biggest cause--and one that patients can help control--is probably the medical misuse of antibiotics. Researchers estimate that nearly half of the antibiotic prescriptions written outside of hospitals are inappropriate. In an unprecedented attempt to turn the tide, the U.S. Food and Drug Administration (FDA) recently proposed putting labels on antibiotics urging doctors to use them only when a bacterial infection is proved or highly likely. And several medical groups are recommending greater restrictions on the preventive use of antibiotics before surgery and for patients with certain heart problems.

On the individual level, antibiotic resistance can cause significant danger and suffering. Hollie Mullin, of Olathe, Kan., started receiving repeated dosages of antibiotics when she was just 3 weeks old to treat what her parents thought were recurrent ear infections. Her mother says the doctors weren't sure Hollie really had all those infections--and the infectious-disease specialist Hollie eventually saw says he doubts it--but the parents wanted treatment and the doctors complied. That repeated, questionable use of antibiotics apparently allowed at least one strain of the bacteria normally living in Hollie's ear to adapt and develop resistance to those drugs--and possibly to other, related drugs as well. When she did develop a clear-cut bacterial infection a few months later, oral antibiotics didn't work. It took two weeks of an intravenous drug reserved for the most stubborn cases to subdue the infection. Even more important, those newly resistant germs may well have spread into the community, where they could infect other people.

But even when antibiotics are required, choosing the wrong drugs may still produce resistance--and choosing the right ones isn't easy. For example, marketers highlight the ability of many antibiotics to attack a broad range of bacteria. That's a potential advantage when the infecting organisms are multiple or unknown. But choosing a broadspectrum drug when a narrower one would do the job gives many organisms in the body a chance to develop resistance. Similarly, some new antibiotics can be taken less often or for fewer days than other drugs. But if that advantage persuades doctors to prescribe a drug that's not optimally effective, it may eliminate only the weaker strains, letting the stronger ones survive and multiply.

Consider azithromycin (Zithromax), a moderately broad-spectrum antibiotic that's taken just once a day for five days. To promote the drug to pediatricians for treating ear infections, Pfizer created Max the Zebra. Sales reps distribute toy zebras to pediatricians, some pediatric journals come wrapped in zebra-striped paper, and Pfizer gave a live zebra to the San Francisco Zoo.

Max has helped boost Zithromax's sales close to the billion-dollar mark. But the Centers for Disease Control and Prevention (CDC) recently concluded that other antibiotics fight ear infections better than azithromycin, and omitted the drug from its new guidelines for treating the problem.

"We're disappointed by those recommendations," says William Erhardt, M.D., worldwide medical director of Pfizer's anti-infective group. "But we stand by our drug." Erhardt cites studies that the FDA reviewed when it approved the drug for ear infections in 1995. But those studies evaluated symptoms, while the CDC considered studies of bacterial killing, a far more rigorous and reliable measure of drug efficacy.