Beating antibiotic resistance - Brief Article

Healthcare Purchasing News, August, 1999 by Rick Dana Barlow

Optimal dosing, prescription software possible answers

BALTIMORE -- University educators and scientists have been preaching to hospital infection control practitioners for years about the dangers of multidrug-resistant bacteria and how to combat the growing problem.

Certainly it's no secret that overprescribing antibiotics to cure even the most common ailments have spurred the bugs to become smarter and thicken their cell walls. Those who survive the pharmaceutical onslaught multiply and proliferate.

Until now, the drug companies have managed to remain ahead of the game, rolling out the latest wonder product just in the nick of time.

But after nearly 50 years, those days appear to be numbered.

"The window is closing and we're coming to the end of the antibiotic era," said J. Glenn Morris Jr., M.D., who heads the division of hospital epidemiology at the University of Maryland School of Medicine, College Park, MD. "Clearly [antibiotics] are one of our most valuable drugs, but we can no longer anticipate that they will take care of all infections."

Ron Polk, Pharm.D., professor of pharmacy and medicine, Medical College of Virginia at Virginia Commonwealth University, Richmond, put it more succinctly. "All antibiotics lead to resistance," he told attendees at the annual Association for Professionals in Infection Control and Epidemiology conference.

In fact, there's only one antibiotic left potent enough to kill even the toughest bugs - vancomycin. Bacteria such as methicillin-resistant Staphylococcus aureus, are still vulnerable to vancomycin, but for how long is anybody's guess.

"Everyone's worried about [vancomycin-resistant Staph. aureus] because this would be a major calamity in the medical community and for the population at large," Morris said. "Can it happen? The real question is: When will it happen? So far, there have been three cases in the world, two of which were in the United States, where Staph. aureus developed an intermediate resistance to vancomycin. It's only a matter of time before we see full resistance."

Fighting back across the globe

More than 40,000 infection control practitioners, nurses, physicians, pharmacists and other health care officials around the world participated in a satellite videoconference, "Antimicrobial Resistance: Solutions to the Problem," and indicated how they control resistance. The most common responses:

Antibiotic management

More health care facilities are implementing various antibiotic management strategies as deterrents. Early efforts were motivated more by economics and controlling the usage of high-cost drugs, according to Virginia Commonwealth's Polk.

Chief among those strategies are what's known as optimal dosing and optimal duration parameters. Namely, it's how much of a particular antibiotic should be administered and for how long.

"Pharmacodynamics is still trying to figure this out," Polk said. "We know all the details on how [bacteria] develop resistance to antibiotics, but we don't know how much to give."

Some experts contend that more prudent use of antibiotics won't lead to lower resistance, Polk noted. "They believe that once the resistance gene is in the bacterial population, it's too late because the horse is out of the barn," he said. "The optimistic view is that it makes intuitive sense and there's limited data to support it."

Education is one strategy with dubious results, according to Polk. "It depends on how you define education, but a brochure issued from pharmacy is not likely to have an impact," he said

A more effective tactic is direct intervention - either pharmacists accompany doctors during rounds and advise them on writing prescriptions or doctors receive peer feedback through performance evaluations, he said.

Some facilities have adopted stricter measures, such as imposing "required justification" For all antibiotic dispensing, Polk said. These include antibiotic order forms, telephone approvals through pharmacy and automatic stop orders. "These are most onerous to prescribing doctors, but they work he best to reduce the rate of resistance, he said.

Many hospitals rank their antibiotics in three classes: Unrestricted, controlled and restricted. Doctors are allowed to prescribe controlled antibiotics for 72 hours, but they need to gain approval for further dosing. Restricted antibiotics require immediate approval.

The merits of antibiotic cycling/rotation as a potential solution are doubtful as well, according to Polk. That's where clinicians change drugs or therapies to therapeutic equivalents during a specified time period to lessen the likelihood of resistance developing. "By switching drugs, you may just be squeezing the balloon," he said. Resistance may decrease in one area only to increase in another. "This reduces costs, but there's little evidence it reduces resistance," he added.

Polk pointed to computer surveillance as the most promising solution. "Computer-guided antimicrobial prescribing may be the ultimate method for fighting antimicrobial resistance," he said. "The doctor feeds [patient] data into a computer program and the program recommends the appropriate antibiotic therapy. It's relatively non-invasive to surgeons."