More Germs Resisting Cipro, Study Says

Cipro, the antibiotic that became a household word during the 2001 anthrax scare, is becoming increasingly ineffective against dangerous infections because of overuse, a study released today indicates.

The researchers examined data on infections in hospitalized patients in 43 states and Washington from 1994 to 2000. Ailments included respiratory and urinary infections caused by a variety of bacteria.

Many germs had grown resistant to fluoroquinolones, a class of antibiotics that includes ciprofloxacin, known by the brand name Cipro.

In 1994, Cipro was effective against 86% of the bacteria samples analyzed, but that dropped to 76% by 2000, the researchers found.

The anthrax bacterium was not studied, and the researchers said their findings do not mean that Cipro is becoming less effective against anthrax, which rarely affects humans.

The study appears in today’s Journal of the American Medical Assn.

“More judicious use of fluoroquinolone antibiotics will be necessary to limit this downward trend,” said the researchers, led by Melinda Neuhauser of the University of Houston.

Bacteria that became increasingly resistant during the study were all common causes of infection, including E. coli.

Resistance can develop when a drug is used repeatedly against the same germ, which may eventually mutate to outwit the drug. Overuse and inappropriate use of antibiotics also can cause bacteria that normally live in the body to mutate and become infectious.

The growing resistance found in the study came at a time when doctors increasingly prescribed Cipro and similar drugs for common ailments, the researchers said.