With all the talk of "superbugs" and antibiotic-resistant bacteria, you might think prescriptions for unnecessary antibiotics is relatively infrequent, especially for conditions where these drugs rarely work.
New research from Brigham and Women's Hospital in Boston suggests the opposite. Dr. Michael L. Barnett, lead author, and Dr. Jeffrey A. Linder, senior author, found that prescriptions of antibiotics for sore throat and acute bronchitis are far more common than they should be.
"You have a viral infection for which the antibiotics are not going to help, and you’re putting a chemical in your body that has a very real chance of hurting you," Linder said. Side effects of antibiotics include diarrhea, vaginitis in women, interactions with other medications and more serious reactions in a small number of people.
Also concerning: When you take antibiotics, there's a chance the disease you're fighting -- or other bacteria in your body -- will mutate, making it more resistant to antibiotics in the future.
"People may have infections that are harder to treat down the line because we're overusing antibiotics today," Linder said.
Disturbingly, says Linder, if you have taken an antibiotic recently there is a measurable amount of antibiotic-resistant bacteria on and inside you. It's not possible to say any particular person is going to end up with an infection that's resistant to antibiotics because of taking these drugs. But science has shown that community levels of antibiotic use are related to rates of antibiotic-resistant bacteria, Linder said.
Results from two studies by Linder and Barnett were presented at IDWeek 2013, a meeting of health professionals, this week.
In a research letter published in the journal JAMA Internal Medicine, the researchers showed that while only 10 percent of adults with sore throat have strep, the specific condition requiring antibiotics, doctors prescribe antibiotics in 60 percent of sore throat cases.
The study authors used data from large nationally representative surveys of ambulatory care in the United States: The National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey. The surveys are sources of information on physicians and their practices.
Linder and Barnett analyzed data from 1997 to 2010 for more than 8,000 sore throat visits, from patients who did not have injuries, immunosuppression or other infectious diagnoses at the same time. Based on this information, they determined that physicians have been prescribing antibiotics in about 60 percent of sore throat visits since around 2000.
They also found that prescriptions for penicillin, the choice antibiotic for strep throat treatment, held steady at 9 percent, while the more expensive alternative azithromycin has been prescribed more and more. In 1997 to 1998, prescriptions for azithromycin for sore throat were too uncommon to reliably measure; in 2009 to 2010 it was prescribed in 15 percent of visits.
There are limitations to this study, however; the researchers have no way of knowing whether individual prescriptions for antibiotics are appropriate, and the surveys only include patients seen in clinic or emergency department settings.
"The financial cost of unnecessary antibiotic prescribing to adults with sore throat in the United States from 1997-2010 was conservatively $500 million," the study noted. The cost could have actually been 40 times more expensive because of diarrhea and other side effects from antibiotics.
Researchers also found alarming trends regarding antibiotic overprescribing for acute bronchitis using nationally representative surveys. This study, unlike the research letter, has not been published in a peer-reviewed journal but was presented at IDWeek 2013.
Ideally, says Linder, antibiotics would almost never be prescribed for acute bronchitis because of the abundance of evidence that they do not help this condition.
Yet the prescribing rate of antibiotics for acute bronchitis nationally has remained steady over the past 30 years around 73 percent, he said.
Researchers excluded anyone who had a chronic lung disease such as asthma and emphysema from this study.
Why so many antibiotics?
Part of the problem of overprescribing is patient demand -- people ask for antibiotics because they think these drugs will make them feel better. The other side of the coin is that many doctors have been prescribing antibiotics in abundance for years and are following old habits.
"I think there’s a discussion that should be happening between patient and doctor that doesn’t happen, that automatically leads to an antibiotic prescription," Linder said.
If you have a sore throat, for instance, you can tell your doctor that you want to know if you have strep -- and that if you don't have it, you don't need an antibiotic.