CHICAGO — Repeated warnings that antibiotics don’t work for most sore throats and bronchitis have failed to stop overuse, researchers found, saying doctors continue to overprescribe the drugs.
Antibiotics can have bad side effects, including stomach pain and severe diarrhea, and inappropriate prescriptions put patients at needless risk. The practice also can cause drug-resistant germs.
The findings show reducing inappropriate prescribing ‘‘is frustratingly, disappointingly slow,’’ said Jeffrey Linder, a physician and researcher at Harvard Medical School and Brigham and Women’s Hospital. He did the research, covering two analyses of national health surveys from the late 1990s to 2010 and representing more than 2 million annual visits to doctors’ offices or emergency rooms, with Brigham colleague Michael Barnett.
Reid Blackwelder, president of the American Academy of Family Physicians, said part of the problem is old prescribing habits that didn’t change when evidence emerged showing most sore throats and bronchitis are caused by viruses; antibiotics only treat infections caused by bacteria. Antibiotics can treat bacterial pneumonia, most urinary infections, and some types of eye and ear infections.
Patients’ demands and doctors’ time pressures also play a role: It’s often easier to prescribe an antibiotic than to take time to explain why they don’t work, Blackwelder said.
‘‘We’ve all done it,’’ he said.
Ed Septimus, a professor at Texas A&M Health Science Center in Houston, said development of more rapid testing to identify germs that cause sore throats or bronchitis could help curb the practice.
The research was being presented Thursday at an infectious diseases meeting in San Francisco.
One analysis found that antibiotics were prescribed at 60 percent of primary-care and emergency room visits for sore throats in 2010, a rate that didn’t budge over 10 years but was down from about 70 percent in the 1990s. That study was published online Thursday in JAMA Internal Medicine.
In an editorial, Dr. Rita Redberg, the journal’s editor, noted that only about 10 percent of sore throats are caused by strep bacteria — which antibiotics can treat.
The second analysis found antibiotics were prescribed at 73 percent of all visits for bronchitis in 2010, a rate that didn’t change from 1996. Only rare cases of bronchitis are caused by bacteria.