Subscribe to health news headlines email updates.
THURSDAY, Oct. 3 (HealthDay News) -- Despite efforts to curb the unnecessary use of antibiotics, many doctors still prescribe them for illnesses that don't respond to the medications, Harvard researchers report.
Antibiotics only work against bacterial infections, and yet they are prescribed at a rate of 60 percent for sore throats and 73 percent for bronchitis, conditions that are typically caused by viruses, the scientists said.
"For sore throat, antibiotics should be prescribed about 10 percent of the time," said study author Dr. Jeffrey Linder, a researcher in the division of general medicine and primary care at Brigham and Women's Hospital in Boston.
Although the U.S. Centers for Disease Control and Prevention encourages the proper use of antibiotics, their use for sore throats has only dropped from about 70 percent of doctor visits in 1990 to 60 percent of visits now, he said.
"The story for bronchitis is even more bleak," Linder said. "The antibiotic prescribing rate was 73 percent and the right prescribing rate for bronchitis, according to guidelines, is zero," he said. "That hasn't changed at all over the last 30 years."
Linder thinks these rates remain high because, on the one hand, patients demand antibiotics from their doctors and, on the other hand, doctors don't want to miss a more serious condition such as pneumonia or strep throat.
"There's plenty of blame to go around," he said. "It's a lot easier to write a prescription than to have a five-minute conversation about why antibiotics aren't necessary.
"We need to have more faith in our bodies to get better from what are self-limiting conditions," he added. "The vast majority of sore throats, and virtually all of bronchitis [cases], get better on its own."
The report on sore throats was published online Oct. 3 in JAMA Internal Medicine, and the results of the bronchitis study are scheduled for presentation Thursday at ID Week 2013 in San Francisco.
Research presented at medical meetings is typically considered preliminary until published in a peer-reviewed journal.
Dr. Marc Siegel, an associate professor of medicine at the NYU Langone Medical Center in New York City, said, "This isn't new -- we are not listening."
"This leads to more antibiotic-resistant bacteria, and when we do that we don't have the antibiotics when we need them because the body has developed resistance," he said.
Siegel said the true cost of antibiotic overuse is not in the cost of the pills themselves, but rather in the consequences of treating diseases caused by antibiotic-resistant bacteria such as MRSA (methicillin-resistant Staphylococcus aureus) and Clostridium difficile.
"This is going to be an enormous financial burden on the health care system," he said.
Linder is more concerned with the potential harmful side effects of antibiotics when they are used for conditions they can't treat.
"There is concern about antibiotic overuse causing super bugs and things we are not going to be able to treat down the line," Linder said. "I think what's missing from the conversation is the fact that we are prescribing and people are taking a medicine that has nearly a zero chance of helping them and a very real chance of hurting them."
These side effects can include allergic reactions, diarrhea, yeast infections for women, rashes or adverse interactions with other drugs, he said.
For the study, Linder and his colleague, Dr. Michael Barnett, looked at the changes in prescribing antibiotics for sore throat and acute bronchitis from 1996 to 2010.
The data included some 39 million adults with acute bronchitis and 92 million with sore throat seen by primary care physicians or in emergency departments.
Linder and Barnett found that while visits for sore throats dropped from 7.5 percent of primary care visits in 1997 to 4.3 percent in 2010, the rate at which antibiotics were prescribed didn't change, with doctors prescribing them 60 percent of the time.
In addition, emergency department visits for bronchitis increased from 1.1 million in 1996 to 3.4 million in 2010, and prescriptions for antibiotics to treat bronchitis rose from 69 percent to 73 percent.
Prescriptions for penicillin, the antibiotic recommended for strep throat, stayed at 9 percent, the researchers reported.
For more on antibiotics, visit the U.S. National Library of Medicine.