Have you ever felt miserable with a cold, hoping a quick antibiotic would make you feel better right away? Unfortunately, antibiotics aren’t a magic bullet for all illnesses. While they can be lifesavers for bacterial infections, they won’t help against viruses — the culprits behind colds. In fact, taking antibiotics unnecessarily can actually be harmful. This post will explain why antibiotics don’t work for colds, the risks of overuse, and how doctors decide if you truly need them. Plus, we’ll hear directly from medical professionals about how they approach antibiotic use and what factors they consider.
Antibiotics are meant for bacterial infections, not viral infections.
When you have symptoms that resemble a cold, the doctor will not and should not give you antibiotics. Colds are caused by viruses, and antibiotics are not effective against them. For a while, doctors were prescribing antibiotics any time someone asked for them, but antibiotic resistance has become a major issue, so there’s been a huge push to prescribe antibiotics less often. “We need to deemphasize patient satisfaction and immediate gratification with prescribing of antibiotics for viral infections, including for pediatric patients,” says Thy N. Le, PharmD, BCPS, who ran antimicrobial stewardship programs at two different hospitals in New York City.
Why don’t antibiotics work for viral infections?
Antibiotics are not effective for treating viral infections because viruses are completely different than bacteria. Antibiotics target specific structures on bacteria that viruses don’t have or are different in viruses. The beauty of antibiotics is that they are mostly specific to bacteria and do not attack and kill our cells. Some can cause damage to our cells, but not to the same extent that they kill or slow the growth of bacteria.
What’s the problem with getting antibiotics when you have a viral infection?
You should not get antibiotics for a viral infection for several reasons. First of all, your body is full of bacteria, especially in your gut. These bacteria are part of our microbiome, our companions that help teach our immune system how to function properly, digest our food, and many other wonderful things. We do not want to kill these bacteria. But when you take antibiotics, whether or not you have an infection, these guys suffer collateral damage. Sometimes, when the microbes in our bodies endure the onslaught of antibiotics, other infections can result, like yeast infections.
A significant risk of receiving antibiotics, both when you do and do not need them, is the possibility of killing the majority of microbes in your gut, leaving potentially antibiotic-resistant species to proliferate. In some serious cases, C. diff or Clostridium (now Clostridioides) difficile infections arise this way — these infections can be life-threatening. (See my post on C. diff infections and fecal transplants.) And they wreak havoc on your gut. Some people even die from these infections, which was the case for my grandma.
In addition to the effect that antibiotics have on microbes that inhabit your body under normal circumstances — your microbiota — is that they can cause other side effects, including rashes, dizziness, and nausea.
How do the doctors know if we should get antibiotics or not?
Doctors have a process for determining if you need antibiotics. They initially look at your symptoms to determine whether you have an infection because you may be suffering from some other ailment.
They can get a good idea of whether or not you are suffering from a cold, which would not require antibiotics, or if you have some symptoms that resemble a bacterial infection. Doctors can also tell if you have a bacterial infection or not by diagnostic tests such as microscopy (looking to see if there are bacterial cells at the site of infection, like in your urine in the case of a UTI) or attempting to culture bacteria from the site of infection.
According to Ilan Schwartz MD PhD, an Assistant Professor in the Division of Infectious Diseases, Department of Medicine, Faculty of Medicine & Dentistry, University of Alberta, doctors ask the following questions:
- Does the patient have an infection, or is it something else?
- If they do have an infection, what kind is it? Can we run a test to determine its type? How long will the test take?
- Is there a treatment?
You have to determine “what you think is the diagnosis, whether you are likely to get more information to confirm or refute this suspected diagnosis, and the risks and benefits of therapy versus no therapy,” says Dr. Schwartz. “If the benefits of treating seem to outweigh the risks of treating (i.e. the benefits of not treating), then you prescribe.”
The location of the infection can be a pretty good indicator of whether or not you have a bacterial infection and, therefore, should or should not receive antibiotics. Often whether a patient should be prescribed antibiotics or not will depend on what part of the body is infected. Respiratory and sinus infections tend to be viral. “And with the sinuses in particular, even if it is a bacterial infection, these tend to get better without anything, so the risks/side effects of antibiotics is higher than the potential benefit, and for the most part we should avoid antibiotics,” says Assistant professor in the division of Infectious Diseases at the University of Alabama at Birmingham and the co-chair of antimicrobial stewardship at the Birmingham VA Medical Center Todd McCarty, MD. Skin and urinary tract infections (UTIs), on the other hand, tend to be bacterial.
If more than one antibiotic would be effective for the infection, “I select the most optimal antibiotics without causing harm to the patient with consideration for age, renal/liver function, source of infection, microbiologic cultures, bioavailability, route of administration,” says Dr. Le.
The decision to prescribe antibiotics can be difficult and must be done with great caution and care. Prescribing antibiotics unnecessarily can have effects both in the broad sense for antibiotic resistance development in bacteria and in the narrow sense for the individual patient. Next time you go to the doctor, you’ll be armed with the knowledge that sometimes it’s best to avoid getting that solution in pill form, and you simply need to wait it out.
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