Federal officials hold meeting to discuss their plans for fighting antibiotic resistance.
With the latest data showing little abatement in the rise of antimicrobial resistance in the United States, federal health officials said they are moving on several fronts to try to control the spread of defiant disease-causing bugs.
Officials said recently that they are using a combination of regulatory changes, drug company incentives, and educational campaigns as part of a coordinated effort to keep the nation's Rx armamentarium ahead of resistant organisms.
But conquering the problem seems difficult as public health authorities battle both patients' desire for antibiotics and a relatively dry pipeline of novel antibiotics at U.S. pharmaceutical firms.
Recent surveillance figures from the Centers for Disease Control & Prevention show that, on average, 41.3% of Staphylococcus aureus isolates in this country are resistant to methicillin, though geographic resistance rates swing from 7% to as high as 60%. More than 120,000 persons were hospitalized with MRSA in 2001, and the numbers have been "inching up every year," said J. Todd Weber, M.D., director of CDC's National Center for Infectious Diseases.
Some progress against overprescribing of antibiotics has been made, Weber told an audience at a recent meeting in Bethesda, Md., called to review the activities of the Interagency Task Force on Antimicrobial Resistance. The task force was created by an act of Congress in 2000 after Sens. Edward Kennedy (D, Mass.) and Bill Frist (R, Tenn.) held hearings on Capitol Hill on the problem of widespread drug resistance in the United States.
Data published in 2002 showed that prescribing to children less than 15 years old was down from a high of more than 800 Rxs per 1,000 kids to around 500 per 1,000. But, at the same time, newer broad-spectrum agents such as Augmentin (amoxicillin and clavulanate, GlaxoSmithKline), azithromycin, and clarithromycin have all seen increased use. "The news is not all good," Weber told the group.
Part of the problem is that drug companies have been slow to put next-generation antimicrobials on the market, experts said. Of 15 new antimicrobials approved by the Food & Drug Administration since 1998, seven have been for a single infection: HIV. And diminishing effectiveness of highly active antiretroviral therapy has now led CDC to begin testing newly infected HIV patients for resistance in 26 states.
"There's not much in the pipeline in terms of traditional drugs," said Marissa Miller, the antimicrobial resistance project officer at the National Institutes of Allergy and Infectious Diseases.
"It's become obvious that those [drugs] really aren't meeting all of the needs," added John H. Powers, M.D., lead medical officer for antimicrobial drug development at the FDA's Center for Drug Evaluation and Research. He said that the FDA is moving to change the labeling on up to 669 approved drugs, warning physicians and pharmacists about the risks associated with inappropriate prescribing.
The agency is also trying to use surveillance data to make a priority list of bugs for drug companies to target with new products, Powers said. Developing a drug for a bug on the list could earn a company an expedited FDA review lasting six months instead of the normal 10, he said. "We're actually doing this because the drug companies have asked us to," he added.
Powers also said the FDA is considering an additional incentive that would relax data requirements for companies seeking new indications for existing drugs. Current FDA guidance requires companies to submit two separate placebo-controlled studies in support of an application for a new indication. But for drugs with potential use against resistant organisms, the agency will soon consider allowing companies to submit a single placebo-controlled study along with data from a biologically similar pathogen or a similar active agent.
Meanwhile, the National Institutes of Health is spending $6 million testing novel therapeutic agents with a potential to battle a range of resistant organisms. Successful early candidates will then go to private drug companies for clinical testing, Miller said.
CDC officials said they would not leave the public out of their battle against antimicrobial resistance. The agency is preparing to launch a national media campaign this September urging consumers to "get smart" about how antibiotics work and why overuse is bad for public health. (For more on new treatments for infectious diseases, see "Officials offer sobering infectious disease outlook".)
Todd Zwillich. Officials try incentives, PR against spreading drug resistance. Drug Topics Aug. 4, 2003;147:36.