Antibiotic Resistance: Part 2

by Food and Drug Administration (FDA)

(Page 2 of 2)

Too Much of a Good Thing

Experts say that doctors are sometimes quick to prescribe antibiotics for all sorts of symptoms, even though antibiotics work only against bacterial infections, not viruses such as the flu or the common cold. More than 50 million of the 150 million antibiotic prescriptions written each year for patients outside of hospitals are unnecessary, according to a recent CDC study.

Sometimes, doctors lack knowledge about the symptoms and natural course of respiratory illnesses, which contributes to overuse, according to a CDC editorial in the Sept. 17, 1997, Journal of the American Medical Association. Also, many doctors have told CDC they sometimes write prescriptions simply to meet patient demands.

Patients therefore must take some of the responsibility for the overprescribing problem, according to Stuart Levy, M.D., director of Tufts University's Center for Adaptation Genetics and Drug Resistance. "Patients have been left out of the formula. Overuse of antibiotics was felt to be a physicians' problem when it is really as much a patient problem."

Patients can do their part to help curb resistance:

Don't demand an antibiotic when the health-care provider determines one isn't appropriate.

Finish each prescription. Even when the symptoms of an illness have disappeared, some bacteria may still survive and reproduce if the patient doesn't complete the course of treatment.

Don't take leftover antibiotics or antibiotics prescribed for someone else. These antibiotics may not be appropriate for the current symptoms, and taking the wrong medicine could delay getting appropriate treatment and allow bacteria to multiply.

For more tips on proper antibiotic use, visit the Website of the Alliance for the Prudent Use of Antibiotics (www.healthsci.tufts.edu/apua/patient.htm).

Even when used carefully, all organisms can develop some resistance to antibiotics over time. "It is a perfectly natural phenomenon for a living organism to develop the means of survival in a hostile environment," wrote French microbiologist Jacques Acar in a 1997 article in World Health.

Preventing infection in the first place may therefore be the best defense against an antibiotic-resistant infection.

Frequent and thorough hand washing is one key to preventing the spread of infection. Good kitchen habits, such as storing foods at the proper temperature, washing fruits and vegetables thoroughly, and cooking foods completely, can also reduce the chance of getting a food-borne illness.

"Take your basic precautions," Bell advises. "That means practicing common hygiene, as well as food safety in your kitchen."

Animal Use: Medicine and More

While the numbers have not been established with certainty, drug resistance expert Stuart Levy, M.D., has estimated that, of the 50 million pounds of antibiotics produced in the United States, over 40 percent are used not to treat human disease but for farm animals and agricultural crops.

Writing in the May 7, 1998, New England Journal of Medicine, Levy states that some 20 percent of this amount is used in therapeutic doses to treat sick animals. The rest is used in lower doses to promote food animals' growth, prevent disease in an entire herd or flock, or protect crops from disease.

Scientists fear that certain bacteria that develop resistance in animals can then infect people who eat meat or other animal products. It is difficult to measure precisely the impact on human health of the use of antibiotics in farm animals, but experts believe that, already, resistant strains of Salmonella, Campylobacter, Enterococcus, and E. coli have been transmitted from animals to people.

But farmers count on antibiotics to keep their animals healthy, and healthy animals, experts point out, may translate into a safer and more abundant U.S. food supply. Keeping in mind the vital protective role of antibiotics in the food chain, FDA's Center for Veterinary Medicine, the World Health Organization, the Centers for Disease Control and Prevention, and the animal industry are seeking ways to prevent the overuse and misuse of antibiotics in animals, while not interfering with necessary uses. FDA's Center for Veterinary Medicine and CDC are working with the American Veterinary Medical Association to develop recommendations and an educational campaign on the judicious veterinary use of antimicrobials.

One issue that is receiving ongoing attention is the use of fluoroquinolones in food animals. The agency approved drugs in this class of antibiotics in 1995 to treat disease in poultry and in July 1998 to treat disease in cattle. The agency has banned other, unapproved uses of fluoroquinolones. At a WHO meeting in Geneva earlier this year, which included FDA representatives, participants urged further research into the public health impact of fluoroquinolone use in animals.

For any animal drug that raises a public health concern, FDA may begin to require evidence before approval that it will not create drug-resistant food-borne pathogens that can harm human health. But drug resistance may be difficult to predict based solely on preapproval studies, says Sharon Thompson of the agency's Center for Veterinary Medicine, so the agency may also require companies to monitor their animal antimicrobials for drug resistance once they are on the market. FDA plans to have a public meeting as early as this fall to discuss whether the agency should require drug sponsors to conduct such studies.

In addition to information collected by the drug company, FDA, CDC, and the U.S. Department of Agriculture look for trends toward resistance in humans and animals through the National Antimicrobial Resistance Monitoring System. Under this key part of FDA's strategy to address antibiotic resistance, scientists collect Salmonella, E. coli, and Campylobacter from sick animals and humans, healthy farm animals, and animal carcasses, and check if the bacteria are becoming less susceptible to any of 17 antimicrobial drugs.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.