It’s understandable that when you’re sick, or when someone you’re caring for is sick, all you want is a medicine that will make everything better.
Unfortunately when it comes to viruses—such those that cause COVID-19, colds or influenza (flu), and other viral illnesses— antibiotic medicines don’t work. In fact, taking antibiotics to try and treat viral illnesses might make us all sicker in the future.
How antibiotics work
Antibiotics were discovered by a scientist called Alexander Fleming in 1928, and are widely credited as one of the most important medical discoveries in human history.
Antibiotics are used to treat infections caused by bacteria. Bacteria are very small organisms, and billions of them live in and on your body. Most of the time these bacteria are harmless or even helpful for your body, like those that help you to digest food, but some bacteria can cause diseases.
There are two types of antibiotics that work to stop bacterial infections. Some slow down the growth of bacteria and damage their ability to reproduce and spread, while others kill the bacteria by destroying the bacteria cell walls. The choice of antibiotic depends on the type of bacteria.
Why don’t antibiotics work on viruses?
Viruses are different to bacteria; they have a different structure and a different way of surviving. Viruses don’t have cell walls that can be attacked by antibiotics; instead they are surrounded by a protective protein coat.
Unlike bacteria, which attack your body’s cells from the outside, viruses actually move into, live in and make copies of themselves in your body’s cells. Viruses can't reproduce on their own, like bacteria do, instead they attach themselves to healthy cells and reprogram those cells to make new viruses. It is because of all of these differences that antibiotics don’t work on viruses.
How can we treat Covid-19?
For detailed information on what to do if you test positive for COVID-19, including managing mild symptoms at home, and when to get medical care for yourself, family member or child, please see our blog I have COVID-19—now what?
How can we treat a cold or flu virus?
You might have heard the phrase that a virus has to ‘run its course’. This means waiting for your body’s immune system to fight off the viral infection by itself by activating an immune response. If you have a cold or the flu, during this time you might experience symptoms like:
- a runny or blocked nose
- sore throat
- headache
- fever
- cough
- and muscle aches.
Resting in bed, drinking plenty of fluids (particularly water) and taking over-the-counter medication to relieve symptoms will help you recover from a virus. This is generally enough for otherwise healthy people. In some cases, your GP may prescribe antiviral medications to help reduce the severity and length of your illness.
Most importantly, you can help protect yourself from catching the flu by getting a flu vaccine. The flu vaccine changes every year, so it is important to get a new one before winter each year.
If you have a cold or the flu, you should visit your GP or call 13 HEALTH (13 43 25 84) for further advice if you experience any of the following symptoms:
- shortness of breath or trouble breathing
- chest pain
- a really sore throat that hurts to swallow
- a cough that doesn’t go away after a few weeks
- a headache or sinus pain that won’t go away
- persistent vomiting which means you can’t keep any fluids down
- have a high temperature (38°C or higher)
- feeling confused or disoriented
- or coughing up coloured phlegm.
What’s wrong with taking antibiotics ‘just in case’?
Like any living organism, bacteria can evolve and adapt to changing environments. This means that bacteria can become ‘resistant’ to antibiotics, if exposed to them enough. The video below explains how this can happen.
As bacteria become resistant to antibiotics, the risk grows that harmful infections caused by bacteria can no longer be treated because we don’t have any tools left to fight them. Taking antibiotics when they aren’t needed can increase this risk for everyone and make antibiotics less effective overall.
Taking antibiotics when you don’t need them is a waste and puts you at risk of side effects, like a rash, upset stomach or diarrhoea. It can also mean that they won’t work when you really need them for a serious infection.
More information
- Queensland Health | What you need to know about antibiotic resistance
Last updated: 4 March 2022
For many common infections, clear guidelines exist for when antibiotics should be used and when they should not. For example, antibiotics cannot cure viral illnesses like the flu or the common cold, so there is no benefit to taking them for these conditions. Further, unnecessary use of antibiotics puts patients at risk for avoidable adverse effects. And yet, inappropriate antibiotic prescribing continues to be prevalent in the U.S.
Recent research from the Centers for Disease Control and Prevention and The Pew Charitable Trusts shows that nearly 1 in 3 antibiotics prescribed at outpatient facilities—including physician’s offices, emergency departments, and hospital-based outpatient clinics—is unnecessary, amounting to 47 million prescriptions a year.
So why is there so much inappropriate prescribing of these lifesaving drugs? Many factors drive this unnecessary use, including:
- Patient satisfaction and pressure. Patients or their families may expect to get a prescription at an office visit, whether or not an antibiotic is necessary. And even when there is no expectation of antibiotics from patients or their families, doctors may think there is. Studies show that physicians can be affected by this pressure—real or perceived—and as a result are more likely to prescribe antibiotics.
- Time constraints. In outpatient settings, doctors often have limited time to see patients, diagnose their illnesses, and formulate a treatment plan. Interviews with doctors reveal that they may quickly prescribe antibiotics because they want to avoid lengthy explanations of why the drugs are not needed and because a shorter office visit allows them to see more patients. In at least one study of general practitioners, busier physicians who see more patients prescribed antibiotics at a higher rate than did their less busy colleagues.
- Decision fatigue. The process of repeatedly diagnosing and treating large numbers of patients may also affect a doctor’s capacity to make consistent prescribing decisions. This decline in decision-making abilities after having to make repeated treatment choices is known as decision fatigue and may contribute to inappropriate antibiotic use. For example, a recent study showed that as their workdays wore on, physicians became significantly more likely to prescribe antibiotics to patients with acute respiratory infections—conditions for which these drugs are only rarely recommended.
- Uncertain diagnoses. Patients with viral and bacterial infections often have similar symptoms—congestion, cough, sore throat—making it difficult for physicians to differentiate between the two in the absence of a diagnostic test. In these cases, doctors may go ahead and prescribe antibiotics because they perceive the risk of not prescribing them as greater than that from unnecessary antibiotic use.
- Assuming that other doctors are the problem. In some cases, even when doctors agree that antibiotic overuse is a major problem or know that the drugs are not appropriate for a specific condition, they may not think their individual practices, or those of peers in the same medical specialty, contribute significantly to the problem. Rather, studies show that physicians attribute inappropriate prescribing to other clinicians or blame other areas of medicine.
Understanding the underlying behavioral drivers that contribute to inappropriate antibiotic prescribing can help guide the development of effective antibiotic stewardship. And some researchers have already started integrating behavioral science techniques into stewardship strategies, with some encouraging findings.
For example, one study showed that physicians whose offices displayed a “commitment poster” explaining their pledge to follow guidelines for appropriate antibiotic prescribing and the reasons why the drugs are not always needed, had a 20 percent lower rate of inappropriate prescribing than those not displaying a poster. Other studies using interventions that target behavioral drivers have also shown promise. One required that doctors provide a justification in the patient chart when antibiotics were prescribed for conditions for which antibiotics are not indicated, and another ranked physicians based on their level of inappropriate prescribing (i.e., those with higher rates of inappropriate prescribing were told they were “not a top performer”). Both led to significant reductions in inappropriate prescribing compared with conventional approaches.
Deciding whether or not to prescribe an antibiotic can be a complex process, during which physicians are influenced not only by medical information, but also by their interactions with patients, the uncertainties that surround medical decision-making, and the organizational challenges of delivering care in busy outpatient settings. By understanding the factors that affect physicians’ antibiotic prescribing decisions and applying concepts from the social and behavioral sciences, inappropriate prescribing can be reduced—which in turn can reduce the threat of resistance.
David Hyun, M.D., works on The Pew Charitable Trusts’ antibiotic resistance project.