October 16, 2013
Very Few Antibiotic Prescriptions for Sore Throat, Bronchitis, Are Appropriate

San Francisco—Very few of the antibiotic prescriptions pharmacist fill for sore throat or acute bronchitis are warranted, according to new study finding that an overwhelming majority of patients with the viral ailments receive prescriptions for the drugs, even though they should not.

At a presentation at ID Week 2013 as well as in a research letter published recently in JAMA Internal Medicine, Harvard University researchers reported that clinicians prescribed antibiotics in 60% of visits for sore throats and 73% of visits for acute bronchitis, based on their analysis of the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey. They note that the antibiotic prescribing rate should be about 10% for sore throats and almost zero for acute bronchitis.

The news wasn’t all bad, however, according to the study background.

“We previously found that the antibiotic prescribing rate for adults making a visit with sore throat dropped from about 80% to 70% around 1993,” the authors write. “Since then, the Centers for Disease Control and Prevention and others have continued efforts to reduce inappropriate antibiotic prescribing.”

The concern, according to the article, is that while antibiotic stewardship programs have been quite successful in hospitals, they aren’t always reaching the community. The authors note that inappropriate use of antibiotics promotes the development of drug-resistant bacteria.

“Also, people need to understand that by taking antibiotics for viral infections, they’re putting something in their bodies that they don’t need,” said senior author Jeffrey A. Linder, MD, MPH, associate professor of medicine at Harvard Medical School and associate physician at Brigham & Women's Hospital in Boston. “Taking antibiotics unnecessarily exposes people to adverse drug reactions, allergies, yeast infections and nausea, with no benefit.”

While sore throats caused by streptococcus bacteria should be treated with antibiotics, Linder pointed out that isn’t the cause of a sore throat about 90% of the time. The research letter notes that prescription of broader-spectrum, more expensive antibiotics, especially azithromycin, was common when Group A Streptococcal (GAS) disease was documented. On the other hand, prescribing of penicillin, which is guideline-recommended, inexpensive, well-tolerated, and to which GAS is universally susceptible, remained infrequent.

With acute bronchitis, Linder added, antibiotics usually are only necessary if pneumonia develops.

For the assessment of the antibiotic prescribing rate for sore throat, researchers determined there were 94 million visits to primary care physicians and emergency rooms for sore throats between 1997 and 2010, based on an extrapolation of 8,191 visits. Antibiotics were prescribed 60% of the time, a decrease from 73% from numbers reported by the same authors in 2001.

The authors note that sore throat visits decreased from 7.5% of primary care visits in 1997 to 4.3% of visits in 2010, with essentially no change in the proportion of sore throat visits to emergency departments (EDs): 2.2% in 1997 and 2.3% in 2010. Physicians prescribed antibiotics at 60% of visits (95% CI, 57%-63%), they add.

Penicillin prescribing remained stable at 9% of visits, according to the results, with azithromycin prescribing increasing from below the threshold of reliable measurement in 1997-1998 to 15% of visits in 2009-2010.

As for acute bronchitis, researchers calculated there were 39 million visits to primary care physicians and EDs between 1996 and 2010, based on an extrapolation of 3,667 actual visits.

That represented a significant increase in the number of visits for acute bronchitis to primary care physicians, from 1.1 million in 1996 to 3.4 million in 2010, and it also meant an increase in the antibiotic prescribing rate in EDs, from 69% to 73%, during the same 14-year period, according to the study.

Noting that their analysis has limitations, including the lack of clinical data to indicate if any individual antibiotic prescriptions are appropriate, the authors write, “Antibiotic prescribing to patients who are unlikely to benefit is not benign. All antibiotic prescribing increases the prevalence of antibiotic-resistant bacteria. The financial cost of unnecessary antibiotic prescribing to adults with sore throat in the United States from 1997 to 2010 was conservatively $500 million. However, antibiotics might have been up to 40-times more expensive.

“For individuals, antibiotic prescribing leads to patients developing diarrhea in 5% to 25% of cases; at least 1 in 1000 patients visits an ED for a serious adverse drug event.”

The report’s conclusion notes “only incremental improvement in antibiotic prescribing for adults making a visit with sore throat.”

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