Do You Really Need That Antibiotic?

Chasing away an infection with the right antibiotic can feel magical.

Stabbing throat pain improves, coughs subside, ear aches fade. A course can save us from pneumonia and protect us during surgery. The advent of penicillin has been hailed as one of the greatest discoveries in medicine.

But an antibiotic can also be a temptress. While the drugs work by killing or inhibiting the growth of bacteria, we often seek them out for runny noses and chest colds, most of which are caused by viruses. An estimated 28 percent of antibiotics prescribed to children and adults are unnecessary. When a virus like those that cause the flu or Covid is causing your symptoms, antibiotics not only don’t help, they can hurt.

Swallowing an antibiotic is like carpet-bombing the trillions of microorganisms that live in the gut, killing not just the bad but the good too, said Dr. Martin Blaser, author of the book “Missing Microbes” and director of the Center for Advanced Biotechnology and Medicine at Rutgers University. Drug-resistant bacteria are already in all of us; beneficial bacteria help keep them controlled. When an antibiotic wipes out beneficial bacteria, the resistant bugs can flourish, making present and future infections harder to treat. With the overuse of antibiotics, our microbes are disappearing, a crisis with far-ranging consequences scientists don’t fully understand yet. “I think the health profession in general has systematically overestimated the value of antibiotics and underestimated the cost,” Dr. Blaser said.

Antimicrobial resistance is one of the top global public health threats, according to the World Health Organization. Each year in the United States, an estimated 2.8 million antimicrobial-resistant infections occur, leading to more than 35,000 deaths. If you take a lot of antibiotics, you are at greater risk of developing an antibiotic-resistant infection and spreading it to others. That can contribute to the rise of antibiotic-resistant bacteria, sometimes referred to as superbugs. To top it off, taking antibiotics regularly may also make you more susceptible to other illnesses.

Antibiotics also disrupt the good gut bacteria that are responsible for helping with metabolism, digesting food and educating the immune system. Researchers are currently studying whether this can lead to metabolic disorders, such as Type 2 diabetes, and autoimmune diseases. Research in animals suggests it does lead to chronic diseases. The data suggest this is true for humans, too, said Dr. Lauri Hicks, director of the C.D.C.’s Office of Antibiotic Stewardship, but the link between antibiotic use and different chronic diseases requires further study.

In recent years, experts have been pushing for an overhaul of the way we use these medicines. “This is a mindset,” said Dr. Sara Cosgrove, professor of medicine in the division of infectious disease at Johns Hopkins University School of Medicine. “You do have to get yourself out of the traditional — to some degree, American — mindset that antibiotics are always good and don’t cause harm.”