The rate of antibiotics prescribed to nonhospitalized patients decreased by about one-fourth in the 1990s, according to a study presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy in December.
Researchers from the Centers for Disease Control and Prevention analyzed data from two national surveys that included about 2,500 physicians and 500 hospitals annually, as well as 29,000 patient visits for each site per year.
They found that prescription rates dropped from 599 antibiotics prescribed per 1,000 population to 440 antibiotics prescribed, and from 166 antibiotics prescribed per 1,000 patient visits to 127 antibiotics prescribed. Prescription rates, however, did not change in emergency departments and outpatient clinics.
One troubling finding of the study, according to researchers, was an increase in the number of prescriptions for the antibiotics azithromycin and clarithromycin and for quinolones, a class of drugs that includes ciprofloxacin. Prescription rates for azithromycin rose more than 400 percent from 1992 to 1999.
Every time these broad-spectrum drugs are taken, the risk of resistance to them increases, said researchers. They pointed to ciprofloxacin and its importance in treating people who may have been exposed to anthrax. The more a drug like ciprofloxacin is used unnecessarily, the more likely bacteria are to develop resistance to it.
Researchers concluded that efforts are needed to encourage appropriate antibiotic use in emergency departments and hospital outpatient clinics, and more studies are needed to investigate the rise in the number of prescriptions for broad-spectrum antibiotics.
