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When Antibiotics Work For You (And When They Really Don't!)


When antibiotics were introduced, the medical community was in awe as sick patients improved within hours. Before antibiotics hit the scene in the 1940s there wasn’t much in physicians’ arsenals to fight microbes. Diseases like strep throat and ear infections sometimes led to heart complications and hearing impairment; and infections related to childbirth were rampant.

Antibiotics offered a new frontier in medicine.

How the “miracle medicine” works

Bacteria cells differ from human cells in a few key ways. Scientists use these differences as targets to kill the bacteria cells while minimizing damage to the human cells. For example, some bacteria cells have walls surrounding their DNA. When this type of bacteria is identified through culturing in a lab, a doctor can prescribe a class of antibiotic that blocks the bacteria from building that wall, thereby halting its growth and curing the infection.

For bacteria with different structures there are other classes of antibiotics that exploit different aspects of those bacteria cells. An antibiotic that isn’t targeted for the specific bacteria causing the infection might not be effective. Widespread use of antibiotics followed their discovery and they were used for any complaint; with the thought that the medicine would either cure the infection or do not harm. However, the problems with this approach quickly became apparent.

Mutation, selection and your microbiome

“We are seeing more and more antibiotic resistance,” said Richard Martinello MD, medical director, Infection Prevention, Yale New Haven Health. “Antibiotics can apply selection pressure and allow the bacteria to modify their structure in a way that renders a particular class of antibiotics ineffective. Eventually this can reduce our options for treating infections.”

In addition to smarter bacteria, taking antibiotics when unnecessary is not without side effects

“A balance of bacteria live in our intestines,” said Gregory Buller MD, chairman of Medicine and associate CMO, Bridgeport Hospital. “When you change the internal bacteria landscape you can set yourself up for potentially needing more intense forms of antibiotics.”

Robert McLean MD, New Haven regional medical director in Northeast Medical Group, explains that “People should also be aware that some antibiotics can cause diarrhea, yeast infections, and even weaken connective tissues.” McLean adds, “There is also a serious infection known as C.diff, which causes severe diarrhea and inflammation of the colon. These cases typically occur after longer courses of specific antibiotics known to eliminate many normal bacteria in the colon.”

When to avoid antibiotics

“Antibiotics will do nothing for viral infections,” said Dr. Martinello. “There are a few studies highlighting how antibiotics are ineffective for viral infections. One, published in JAMA, involved researchers infecting participants with rhinovirus, the virus that causes the common cold, and giving half of them antibiotics. There was no difference in recovery between the people given antibiotics and people who took nothing. Colds can take weeks to clear and no antibiotic can change the course of a virus.”

Dr. Martinello explains that people may take an unnecessary antibiotic, then get better over time anyway because their immune system cleared the virus, and the medication then gets unearned credit.

Bacterial or viral?

It can be a challenge for physicians to quickly assess if something is viral or bacterial. In many cases it isn’t easy to tell the difference without a lab confirmation which can take days.

“Physicians have to do an individual risk calculation every time they prescribe an antibiotic,” said Dr. Buller. “Some cases require a culture and sometimes it is more prudent to go ahead and give the antibiotic. It takes clinical expertise to make this kind of decision.”

This is one reason why sharing antibiotics is a big mistake. No hand-off of medication can replace a doctor’s evaluation and advice.

“There are more studies coming out showing antibiotics may not be necessary in many cases where we thought they were,” said Dr. Mclean. “For example, people with diverticulitis were routinely given IV antibiotics. Recent studies show that uncomplicated diverticulitis frequently gets better in a week with a fluid diet and no antibiotics. We have seen similar studies regarding uncomplicated skin infections and asymptomatic urinary tract infections.”

Before you dump your unused antibiotics down the drain – Dr. Martinello explains that this can cause antibiotic resistance in the environment, so please return it to your local pharmacy or throw it in the trash instead.

When antibiotics are necessary

When prescribed antibiotics Dr. Buller shares it can be helpful to ask if the medication should be taken with food or not for absorption reasons. He also says some people find probiotics or yogurt with live cultures helpful to ease stomach and intestinal issues sometimes related to the antibiotic medications.

Additionally, Dr. Mclean said it is important for those who think they may have a penicillin allergy to get a confirmation from an allergist since this allergy can limit medicinal options.

The future fight against bacterial infections

There are some experts who believe if we continue on this global trajectory of widespread antibiotic use that we could see a future where our options against bacteria are limited. However, there are currently physicians and scientists discovering novel forms of antibiotics and bringing new hope to the field.

Physicians from Yale New Haven Hospital are collaborating with scientists from Yale University to develop a form of therapy that entails harnessing the power of certain viruses present in our environment, called bacteriophages, to infect and kill bacteria. This type of therapy was discovered a century ago but was largely abandoned with the antibiotic boom. While treatment is still experimental, the goal is to bring this exciting area of research to the bedside one day.