That finding is “concerning,” write the authors of the study, given the role that unnecessary antibiotics are playing in the development of antibiotic-resistant “superbugs,” a growing and urgent public health problem both globally and in the United States.
As background information in the study points out, dentists prescribe a significant proportion — about 10 percent — of antibiotics in the United States. They are also the top prescribers of clindamycin, the antibiotic most associated with potentially life-threatening C. difficile infections.
In 2017, University of Minnesota researchers reported that 15 percent of Minnesota patients diagnosed with C. difficile infections between 2009 and 2015 had received an antibiotic prescription from their dentist prior to developing the infection, and at least half of those prescriptions were for clindamycin.
Each year, about 500,000 Americans develop C. difficile infections, and about 15,000 die from the illness, “making it a substantial cause of infectious disease death in the United States,” according to the Centers for Disease Control and Prevention.
The authors of the new study say their findings underscore the need to include dentists in efforts to reduce the overprescribing of antibiotics.
“I think of dentists as being part of my primary care,” Katie Suda, the study’s lead author and an associate professor of pharmacy at the University of Illinois at Chicago, (UIC) told Chris Dall, a reporter for the University of Minnesota’s Center for Infectious Disease Resistance and Policy (CIDRAP). “They need to be included in this conversation around antibiotic use and prescribing and antibiotic stewardship.”
How the study was done
For their study, Suda and her colleagues used data collected by a large national health claims database between 2011 and 2015. Within that database, they identified slightly more than 168,000 visits made by adults to a dentist that included a before-visit prescription for an antibiotic.
The researchers then looked to see how many of those prescriptions were for high-risk cardiac patients, who are the only patients that national dental guidelines recommend be given an antibiotic before a dental procedure. The concern with these high-risk patients is that manipulation of the gums during a procedure may cause the gums to bleed, allowing bacteria from the mouth to enter the bloodstream and travel to the heart. The result can be endocarditis, a potentially life-threating infection of the inner lining of the heart.
The researchers found that 81 percent of the antibiotic prescriptions they examined were not in agreement with the guidelines. In other words, the drugs were given to patients who had no high-risk heart condition.
People were more likely to receive antibiotics they didn’t need from their dentist if they were women or living in Western states. But no matter what their gender or where they lived, the individuals most likely to get unnecessary antibiotics were those with a prosthetic joint, such as an artificial knee or hip.
More than 43 percent of the antibiotic prescriptions identified in the study were for patients with prosthetic joints. Yet, the recommendation to give antibiotics before dental procedures to patients with prosthetic joints was removed from clinical guidelines in 2013. The American Dental Association says it took that action because no scientific evidence was found to support the practice and because the known risks of taking antibiotics — including developing a C. difficile infection — outweigh the “uncertain benefits.”
The study also found that amoxicillin and clindamycin were the antibiotics most often prescribed by dentists, but clindamycin — the one with the strongest link to C. difficile — was the antibiotic most often prescribed unnecessarily.
“It is alarming that clindamycin was more likely to be inappropriately prescribed than amoxicillin,” Suda and her co-authors write.
A call to action
In her interview with CIDRAP News, Sudra noted that she and her colleagues are now talking with dentists to determine why they may be overprescribing antibiotics.
“What we hear anecdotally is that orthopedic surgeons are pressuring dentists to prescribe antibiotics for those patients with prosthetic joints, even though the guidelines no longer recommend that,” she said.
Sudra and her colleagues express optimism that the situation can be turned around. Earlier this year, the same team of researchers reported on the success of an antibiotic stewardship “intervention” at a UIC dental clinic.
“There has been some success with medical providers, especially pediatricians, in decreasing antibiotic prescribing,” she told CIDRAP News.
“Perhaps some of those strategies can work for dentists,” she added.
FMI: You can read the study in full on the JAMA Network Open website.