Anyone who’s ever been prescribed antibiotics can remember being told to take all the medication because bad things would happen if they didn’t.
Now, researchers say, less may actually be better.
Writing in the latest edition of the journal The BMJ, researchers said public campaigns in the United States, Canada, Europe and Australia – even conducted by the World Health Organization – have advised patients to complete the full dose even if they feel better before that, or they risk promoting antibiotic resistance.
But the evidence actually shows that stopping antibiotics sooner can be a safe and effective way to reduce antibiotic overuse and resistance, they said.
“The idea is deeply embedded, and both doctors and patients currently regard failure to complete a course of antibiotics as irresponsible behavior,” they wrote. “However, the idea that stopping antibiotic treatment early encourages antibiotic resistance is not supported by evidence, while taking antibiotics for longer than necessary increases the risk of resistance.”
The antibiotic courses prescribed for many years have probably been longer than necessary, and unwittingly contributed to antibiotic resistance, said Dr. Bill Kelly, an infectious disease specialist at Greenville Health System.
“Up until very recently, there was next to no research into what the appropriate length of therapy for various infections are,” he said. “Most of the ... data we have comes from papers that say, ‘We treated them for this infection for this many weeks and they got well.’
“But that’s different from saying this is the number of weeks that you need to treat someone for this.”
Antibiotic resistance is a growing global threat.
In the United States, at least 2 million people are infected with bacteria that are resistant to antibiotics every year, making treatment a challenge, and at least 23,000 of them die, according to the U.S. Centers for Disease Control and Prevention.
Superbugs classified as urgent threats by the CDC include the intestinal infection Clostridium difficile; drug-resistant gonorrhea; and Carbapenem-resistant Enterobacteriaceae, like E. coli, which is resistant to most, and in some cases, all, antibiotics.
Methicillin-resistant Staphylococcus aureus, or MRSA; Vancomycin-resistant Enterococcus; multidrug-resistant Pseudomonas aeruginosa; drug-resistant Salmonella; and drug-resistant Streptococcus pneumoniae are among the 12 Superbugs that the agency considers serious threats. There are also “concerning” threats.
That’s because the loss of effective antibiotics hampers the ability to fight routine infections and undermines the treatment of complications in patients with other diseases, such as asthma, diabetes and rheumatoid arthritis – conditions that afflict millions, CDC says.
MRSA alone caused about 80,461 severe infections and 11,285 deaths in 2011, according to CDC, while an unknown “but much higher number” of less severe infections occurred as well. And resistant S. pneumoniae causes about 1.2 million infections and 7,000 deaths a year, CDC reports.
Overuse and misuse of antibiotics is a leading cause of drug resistance.
CDC estimates that about half of all antibiotics aren’t needed or effective as prescribed. And the bacteria that survive develop resistance to the drugs.
In addition, fighting resistant infections costs the nation more than $20 billion annually. And there are few new antibiotics in development.
Is shorter better?
The situation is frightening, said Dr. Anna Kathryn Rye Burch, associate professor of clinical pediatrics at the University of South Carolina School of Medicine and medical director of Palmetto Health Children’s Hospital and its antimicrobial stewardship program, who agrees that antibiotic courses may indeed be too long.
There already are several strains of tuberculosis that are multi-drug resistant, she said, as well as some gastrointestinal bacteria becoming so resistant there is nothing to treat them with anymore.
“Resistance is a huge issue,” added Brittany NeSmith, clinical pharmacist with Bon Secours St. Francis Health System in the Upstate. “And we don’t have new antibiotics like we used to.”
While many of these drugs are no longer useful and safety warnings have been issued on others, such as the fluoroquinolones, only a handful of new antibiotics have come on the market in the past decade, she said.
In the hospital setting, NeSmith said, staff use biomarkers such as temperature and X-rays to determine when patients improve so they can stop antibiotics when they're no longer needed. And like other hospitals, St. Francis has antibiotic stewardship programs to reduce the use of the medicines.
It’s tougher in the out-patient setting, where most antibiotics are prescribed, she said.
But studies now show that shorter courses are as effective as longer courses in almost every instance, Kelly said. And they’re already used in some situations.
For example, nine days of treatment has been shown to be as effective as 14 days for community-acquired pneumonia, he said, with newer papers even suggesting that five days may be just as good.
And the course of antibiotics for simple urinary tract infections has dropped from seven-to-10 days to just one-to-three days, he added.
While that will be the trend in the future – at least for uncomplicated patients – what to do now is an issue, Kelly said. Physicians want to follow evidence-based medicine, he said, but the problem is the evidence is still not well-developed for most infections.
“There is still a lot of work to be done at determining the appropriate length of therapy for various infections,” he said. “Some organisms may need much shorter therapy than other organisms do. We just don’t know what the right course is.”
The researchers said patients are put at unnecessary risk from antibiotic resistance when treatment is longer than necessary, not when it’s stopped early.
So it’s time to drop the message to take all the medication and encourage the public to recognize that antibiotics should be conserved and tailored to individuals, they said.
But telling people to only take medicine until they feel better isn’t the answer, Kelly said.
The better alternative might be for clinicians to prescribe shorter courses initially and extend them if patients don’t respond, he said.
“What’s needed is more research on finding the appropriate length of therapy for all the common infections,” he said. “But these are difficult studies to do.”
Rye Burch said that even though longer courses may promote resistance, changing prescription patterns must be done safely and backed up by data.
But if people do stop the drugs once they feel better, leftovers should be discarded rather than taken again or given to another family who doesn’t feel well, because that also contributes to antibiotic resistance, she said.
In the meantime, she said, antibiotics should only be prescribed when warranted, not for viral infections, even if patients want them.
“We as physicians needs to do a better job of that,” she said.
NeSmith said the Infectious Diseases Society of America looks at prescribing guidelines every 18 months and updates them when needed. So for now, she said patients should continue to take antibiotics as prescribed until more research is done because that’s the best evidence available.
“I don’t think I’d encourage everyone to do as they want,” she said. “It’s not safe until there’s evidence to determine the most appropriate dose.”
To read the full study, go to www.bmj.com/content/358/bmj.j3418.