The trouble with antibiotics

The trouble with antibiotics

By Susan Farrell, M.D.

Harvard Health Blog

Most people are aware of the potential downsides of taking an antibiotic. These side effects can range from allergic reactions to stomach upset, diarrhea, mental confusion and, in some cases, Clostridium difficile colitis — painful colon inflammation caused by a disruption in the normal balance of bacteria in the large intestine.

However, more recently, concerns regarding the emergence of antibiotic-resistant bacteria are increasingly in the news.

“Antimicrobial stewardship” promotes the appropriate use of antimicrobial agents, including antibiotics, in order to improve patient outcomes, reduce drug resistance and limit the spread of infections caused by drug-resistant bacteria. This concept is not new. Calls for optimizing the use of antibiotics, particularly in outpatient settings, have existed for decades. As of 2013, the U.S. Centers for Disease Control and Prevention listed 18 antibiotic resistant microbes. In 2016, the CDC reported that antibiotic-resistant infections affect 2 million people. There are a number of reasons for the increase in bacteria that are resistant to antibiotics, making some of those antibiotics less effective, but inappropriate prescribing and misuse are big contributors. In 2015, the White House National Action Plan for Combating Antibiotic Resistant Bacteria set a goal of reducing inappropriate outpatient antibiotic use by 50 percent by 2020.

A recent study published in the Journal of the American Medical Association (JAMA) reported on the prevalence of inappropriate antibiotic prescriptions written during US ambulatory care visits between 2010 and 2011. The researchers used data from the National Ambulatory Medical Care and National Hospital Ambulatory Medical Care Surveys to collect information on outpatient and emergency department patient visits to estimate when, how, and why providers prescribe antibiotics. Of more than 184,000 patient visits, 12.6 percent were associated with an antibiotic prescription.

The authors noted that variations in prescribing patterns could be related to regional location and the patient’s age, but based on recommended expert guidelines; they estimated that 30 percent of outpatient oral antibiotic prescriptions may have been inappropriate.

Because antibiotic use is the primary driver of antibiotic resistance, it is important to know when an antibiotic is truly necessary. For example, pneumonia and urinary tract infections almost always require antibiotic therapy. In contrast, sinus infections and sore throats may not. While antibiotics are not necessary for most upper respiratory infections, bronchitis and the flu, as many as 34 million antibiotic prescriptions in the 2010-2011 study were written for these very illnesses. While there were some limitations to the study, the results should still give us all pause.

So, where does antibiotic resistance come from? It is important to note that resistance is not a characteristic of an infected person. It is a characteristic of bacteria that have evolved through genetic changes and mutations that elude the bacteria-killing methods of antibiotics. These genetic changes can persist throughout bacterial strains when the genetic code for these mutations is spread between them.

What causes this spread? When antibiotics are used in farm animals as growth enhancers or when antibiotics are prescribed too often or incorrectly for humans, bacteria develop mutations to protect themselves. Inappropriate medical prescribing can occur when an incorrect diagnosis results in an antibiotic prescription or when antibiotics are used for conditions that do not require them, such as upper respiratory infections. In addition, when patients don’t complete a full course of a necessary antibiotic — usually because they are feeling better — any remaining bacteria in the body will be left to grow and change in ways that encourage their own resistance. The use of broad-spectrum, second line antibiotics in the outpatient setting also contributes to the rise of resistance.

Prescribers and patients can help fend off antibiotic resistance

Limiting the spread of antibiotic resistant bacteria will be everyone’s responsibility.

Health care providers who prescribe antibiotics should:

–Use available point-of-care testing to quickly and accurately determine if a bacterial infection is the cause of a patient’s symptoms.

–Follow expert guidelines on the use of antibiotics for specific illnesses and explain these guidelines to patients when discussing treatment options.

Patients can take a more active role in their care:

–Be aware that not all infections need or benefit from antibiotics. Often you will get better in a reasonable amount of time simply by treating symptoms. Of course, do go back to your doctor should you not improve or get worse.

–When getting an antibiotic prescription, ask if that antibiotic is the best choice for the infection you have.

–Take the medication exactly as prescribed.

(Susan Farrell, M.D., is a contributing editor to Harvard Health Publications.)