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Spring 2021 - Safety

Myths & Facts: Antibiotics

To staunch the growing threat of antibiotic resistance, the medical profession is pivotal in properly prescribing antibiotics and educating patients about their appropriate use.

Antibiotics are major lifesavers in medical history, helping to save millions of lives globally. They can be loosely defined as the variety of substances derived from bacterial sources (microorganisms) that control the growth of or kill other bacteria. More recently, synthetic antibiotics (usually chemically related to natural antibiotics) have been produced that accomplish comparable tasks. Classification of antibiotics is based on their chemical structure (Figure), with the level of effectiveness, toxicity and side effects rendered by the same structural group. There are two types of antibiotics: bactericidal, which kill bacteria, and bacteriostatic, which halt the growth of bacteria. In addition, antibiotics’ bacterial spectrum can be either broad to protect against a range of microorganisms or narrow, and they can be administered either orally or by injection.1 

Prior to the 20th century, infections now considered straightforward to treat such as pneumonia and diarrhea caused by bacteria were the No. 1 cause of human death in the developed world. Then, in the late 19th century, Paul Ehrlich, a German physician, noted certain chemical dyes colored some bacterial cells but not others, concluding it must be possible to create substances that can kill certain bacteria selectively without harming other cells. In 1909, Ehrlich developed the first modern antibiotic when he discovered a chemical called arsphenamine was an effective treatment for syphilis. But, it wasn’t until more than 30 years later that the word “antibiotics” was first used by Ukrainian-American inventor and microbiologist Selman Waksman, who in his lifetime discovered more than 20 antibiotics.

In 1928, Alexander Fleming accidentally discovered penicillin when, upon returning from a holiday in Suffolk, he noticed a fungus, Penicillium notatum (P. notatum), had contaminated a culture plate of Staphylococcus bacteria he had accidentally left uncovered. Fleming isolated and grew the mold in pure culture, and he found that P. notatum proved extremely effective even at very low concentrations, preventing Staphylococcus growth even when diluted 800 times, and was less toxic than the disinfectants used at the time. By D-Day in 1944, penicillin was being widely used to treat troops for infections both in the field and in hospitals throughout Europe. And by the end of World War II, penicillin was nicknamed “the wonder drug” and had saved many lives.2

According to the Centers for Disease Control and Prevention’s (CDC) “Antibiotic Use in the United States, 2020 Update: Progress and Opportunities,” the number of antibiotics dispensed per 1,000 population in outpatient pharmacies across U.S. states in 2018, for which the most recent data are available, ranged from 450 to nearly 1,200. What’s more, the report emphasized that antibiotics continue to be prescribed unnecessarily. To combat this excess, antibiotic stewardship programs (improving how antibiotics are prescribed and used) are increasingly being implemented to optimize treatment of patients who have infections and, thus, protect them from harm. Still, the myths surrounding the prescribing and use of antibiotics continue to threaten the population from the growing threat of antibiotic resistance.3

Separating Myth from Fact

Myth: All antimicrobial agents are antibiotics.

Fact: This is a common misconception. Antimicrobials (anti-infectants) are medicines that act across a wide range of organisms, including bacteria, viruses, fungal, protozoa and helminths, that interfere with the vital functions of pathogens, without affecting the host cell. Antibiotics belong to a subcategory of antimicrobials and are prescribed to treat infections caused by bacteria. Antibiotics have the ability to kill and stop the growth of bacteria, and are prescribed based on the likely organisms involved, prevalence of the resistance of the organism, relevant pharmacology and presence of allergy or host factors that may modify pharmacology, the degree of the severity, urgency and the availability of the culture and sensitivity results. Antibiotics are also prescribed to treat systemic infections, postoperative infections and during surgical procedures that are more than four hours of duration, neurosurgeries, cardiothoracic surgeries, implants and in immune compromised patients.4

Myth: Antibiotics should be prescribed for all infections.

Fact: Antibiotics are not the correct choice for all infections. For example, most sore throats, cough and colds, influenza (flu) or acute sinusitis are viral in origin (not bacterial) and do not respond to antibiotics. These viral infections are self-limiting, meaning an individual’s own immune system will usually kick in and fight the virus off.5 Unfortunately, the majority (64 percent) of respondents in 12 countries surveyed by the World Health Organization said they believe viruses such as colds and flu can be treated with antibiotics.6 In fact, using antibiotics for viral infections can increase the risk for antibiotic resistance, lower the options for future treatments if an antibiotic is needed, and put a patient at risk for side effects and extra cost due to unnecessary drug treatment. 

The top-10 infections for which antibiotics can and should be prescribed are acne, bronchitis, conjunctivitis (pink eye), otitis media (ear infection), sexually transmitted diseases, skin or soft tissue infection, Streptococcal pharyngitis (strep throat), traveler’s diarrhea, upper respiratory tract infection and urinary tract infection.5

Myth: Antibiotics should not be taken by pregnant women and young children.

Fact: Antibiotics are commonly prescribed during pregnancy; however, the specific medication must be chosen carefully since some antibiotics are OK to take during pregnancy, while others are not. Safety depends on various factors, including the type of antibiotic, when in the pregnancy the antibiotic is taken and for how long, how much antibiotic is taken and what possible effects it might have on the pregnancy.

Antibiotics generally considered safe during pregnancy include penicillins (amoxicillin, ampicillin); cephalosporins (cefaclor, cephalexin); erythromycin; and clindamycin. Yet, there are other antibiotics believed to pose risks during pregnancy. For example, tetracyclines can discolor a developing baby’s teeth, and they aren’t recommended for use after the 15th week of pregnancy.7

Babies and toddlers can and should take antibiotics to treat a bacterial infection such as a urinary tract infection or bacterial sinusitis. However, since antibiotics also remove some good bacteria (as well as the bacteria causing the infection), they can put children at risk for severe diarrhea caused by Clostridium difficile (C. diff). In fact, the risk for C. diff diarrhea can last for a few weeks, even after a child has stopped taking antibiotics.8

What’s more, a recent study conducted at Rutgers University found children under 2 years old who take antibiotics are at greater risk for childhood-onset asthma, respiratory allergies, eczema, celiac disease, obesity and attention deficit hyperactivity disorder. In the study, the researchers looked at 14,572 children born in Olmsted County, Minn., between 2003 and 2011, 70 percent of whom received at least one antibiotic prescription during their first two years, primarily for respiratory or ear infections. They found antibiotics were associated with metabolic diseases (obesity, overweight), immunological diseases (asthma, food allergies, hay fever) and cognitive conditions or disorders (attention deficit hyperactivity disorder, autism), but effects varied among the different antibiotics. For instance, cephalosporins were associated with the most risk for multiple diseases, and uniquely autism and food allergies. Researchers also found risk increased with more courses of antibiotics and when given earlier in life — especially within the first 6 months. According to the study’s authors, the findings are consistent with the hypothesis that the composition of the microbiome — the trillions of beneficial microorganisms that live in and on our bodies — plays a critical role in the early development of immunity, metabolism and behavior.9

Myth: Antibiotics should not be taken by those with allergies.

Fact: Some believe those with food allergies shouldn’t take antibiotics; however, food allergies are not a contraindication to antibiotics. That said, it is possible for people to have an allergic reaction to an antibiotic. Signs of a mild allergic reaction include red, itchy, flaky or swollen skin; a flat, red area on the skin covered with small bumps; and hives. Severe allergic reactions include skin that blisters or peels, vision problems, severe swelling or itching, toxic epidermal necrolysis and anaphylaxis, which results in throat tightness, trouble breathing, tingling, dizziness and wheezing. 

In addition, there are some issues that can increase the risk of an allergic reaction to antibiotics such as other allergies (for instance, to cats), a family history of antibiotic allergies, frequent use of antibiotics and a long-term illness that makes the immune system more sensitive.10

Myth: Antibiotics don’t cause side effects.

Fact: All medications have side effects, including antibiotics. Antibiotic allergies or hypersensitivity reactions are some of the most common side effects of antibiotics leading to emergency room admission. Other common side effects include mild skin rash, soft stools or short-term diarrhea, upset stomach and nausea, loss of appetite, and fungal (yeast) vaginal infections or oral thrush. Other more severe antibiotic side effects in addition to severe allergic reaction are severe watery or bloody diarrhea, C. diff, stomach cramps and yeast infections in the mouth or vagina (white discharge and severe itching in the vagina or mouth sores or white patches in the mouth or on the tongue).11

Myth: Antibiotics can be discontinued after symptoms subside.

Fact: No, and yes. For years, individuals have been told that if antibiotics are stopped early or if doses are missed, the amount of antibiotic available to kill the bacteria isn’t enough and the bacteria are still able to replicate. In addition, it’s easier for bacteria to become resistant if there is too little antibiotic present, so individuals should always complete their full course of antibiotics and shouldn’t discontinue them even if they feel better.6

Yet, despite how widespread and deep-rooted this belief is, Brad Spellberg, MD, professor of clinical medicine at Keck School of Medicine at the University of Southern California, and chief medical officer at Los Angeles County+University of Southern California Medical Center in Los Angeles, advises “there are no data to support that continuing antibiotics past resolution of signs and symptoms of infection reduces the emergence of antibiotic resistance. To the contrary, studies have repeatedly found that shorter-course therapies are less likely to select out for antibiotic resistance, which is consistent with fundamental principles of natural selection. Every randomized clinical trial that has ever compared short-course therapy with longer-course therapy, across multiple types of acute bacterial infections (including cellulitis, acute bacterial sinusitis, community-acquired pneumonia, nosocomial pneumonia/ventilator-associated pneumonia, complicated urinary tract infections and complicated intra-abdominal infections), has found that shorter-course therapies are just as effective. When evaluated, shorter-course therapies have resulted in less emergence of resistance.” So, Dr. Spellberg proposes a new antibiotic mantra: Shorter is better! “Patients should be told that if they feel substantially better, with resolution of symptoms of infection, they should call the clinician to determine whether antibiotics can be stopped early,” he explains. “Clinicians should be receptive to this concept, and not fear customizing the duration of therapy.12

Myth: It’s OK for individuals to take others’ leftover antibiotics.

Fact: Despite being told to finish the course of antibiotics, patients often fail to do so, leaving them with unused antibiotic prescriptions. But, individuals should not take antibiotics that are left over from past treatments or offered by family and friends for two specific reasons: 1) antibiotics past their date are more likely to cause resistance since the active ingredient may be impaired, and 2) the antibiotic may not be the correct one for the infection, and if so, the infection will be treated incorrectly, increasing the chance of the bacteria becoming resistant.6

Myth: Antibiotics can help with COVID-19 symptoms.

Fact: The SARS-CoV-2 virus, which causes COVID-19, is a virus and will not respond to antibiotics. However, antibiotics are being studied for the treatment of COVID-19. This is the case for azithromycin, which has anti-inflammatory effects and may help reduce an overactive immune response to COVID-19. Specifically, researchers are looking into the effects of the combination of hydroxychloroquine, an anti-malarial drug (hydroxychloroquine has been found to have anti-SARS-CoV activity in test tube experiments), and azithromycin. 

Results from one small-scale study that looked at the effects of hydroxychloroquine and azithromycin on people receiving hospital treatment for COVID-19 in France showed hydroxychloroquine significantly reduced the viral load or eliminated the coronavirus. And, the addition of azithromycin increased the effectiveness of hydroxychloroquine. However, another study that looked at 1,438 people receiving hospital treatment for COVID-19 in New York, all of whom had similar age, race and time of starting treatment, found treatment with hydroxychloroquine and azithromycin did not improve outcomes, and increased the risk of cardiac arrest. Since then, the U.S. Food and Drug Administration has revoked the emergency use authorization for hydroxycholoroquine.

Nevertheless, doctors are prescribing antibiotics to those with COVID-19. This treatment is needed when the virus causes a respiratory infection that can weaken the immune system, which can increase the risk of getting a bacterial infection that can be harder to fight off. Some doctors also prescribe antibiotics to people with COVID-19 to prevent or treat secondary bacterial infections such as bacterial pneumonia.13

Myth: People’s bodies become resistant to antibiotics.

Fact: It’s not the body but rather the bacteria that becomes resistant to an antibiotic. Antibiotic resistance happens when the germs no longer respond to the antibiotics designed to kill them, which means the germs are not killed and continue to grow.

Myth: Antibiotic resistance only happens when they are taken repeatedly.14

Fact: Antibiotic resistance can occur whenever an antibiotic is taken, whether it is a single course or multiple repeat courses. The more courses taken, the more resistance can occur. But that doesn’t mean it doesn’t occur with a single course. In addition, a single course of antibiotics can lead to life-threatening unwanted side effects and potentially catastrophic changes to the normal bacteria that live in our guts. The imbalance can allow dangerous bacteria like C. diff to predominate and cause severe diarrheal illness.6

Myth: The medical profession is responsible for antibiotic resistance.

Fact: According to CDC, approximately 47 million unnecessary antibiotics are prescribed to patients each year. Yet, while many people quickly associate the health sector alone with the rise of antibiotic resistance, other industries have been influential, too. For example, agricultural professionals once regularly used antibiotics to promote animal growth, a practice that is now prohibited.

There are measures the medical profession can take to reduce the number of unnecessary antibiotic prescriptions. For instance, one case study of a rapid testing system that confirms cases of respiratory viruses in less than an hour shows using such methods could reduce the instances of people getting antibiotics when they don’t need them. And, if doctors don’t have access to such tests, they should resist pressure from patients who ask for antibiotics in cases where they’re not warranted. That often means educating patients about how antibiotics don’t treat viral infections and giving them suggestions of interventions that should help.15

Antibiotic stewardship, the effort to measure and improve how antibiotics are prescribed by clinicians and used by patients, is another method for reducing unnecessary antibiotics use. According to the American Academy of Pediatrics (AAP), antibiotic stewardship is dedicated to using antibiotics only when necessary, and using the appropriate spectrum of activity, dose, route and duration of therapy to optimize clinical outcomes while minimizing harm. In January, the AAP Committee on Infectious Diseases and Pediatric Infectious Diseases Society published a new policy statement regarding antibiotic stewardship in pediatrics.16

Dispelling the Myths Now

The key to curbing the growing threat of antibiotic resistance involves spreading the word about responsible antibiotic prescribing and use. Held annually since 2015, World Antimicrobial Awareness Week is a global campaign that aims to increase awareness of antimicrobial resistance worldwide and to encourage best practices among the general public, health workers and policymakers to avoid the further emergence and spread of drug-resistant infections. Also in November each year, the U.S. Antibiotic Awareness Week is held as an annual observance that gives participating organizations an opportunity to raise awareness of the importance of appropriate antibiotic use to combat the threat of antibiotic resistance. As part of this effort, the CDC’s Be Antibiotics Aware is an educational effort that provides partners with up-to-date information to help improve human antibiotic prescribing and use in the United States.17


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6. Mendelson M. 7 Myths About Antibiotics, Nov. 20, 2015. Accessed at

7. Tobah YB. Is It Safe to Take Antibiotics During Pregnancy? Accessed at,to%20take%20during%20pregnancy%2C%20while%20others%20are%20not.

8. Information About Antibiotic Use in Children. Accessed at

9. Rutgers University. Antibiotic Exposure in Children Under Age 2 Associated with Chronic Conditions, Nov. 16, 2020. Accessed at

10. Antibiotic Medication Allergy. Accessed at

11. Anderson LA. Common Side Effects from Antibiotics, and Allergies and Reactions. Accessed at

12. Spellberg B. Antibiotics: 5 Myths Debunked, Feb. 15, 2021. Accessed at

13. MedicalNewsToday. Can Antibiotics Treat COVID-19 (Coronavirus)? And Other Treatments. Accessed at

14. Centers for Disease Control and Prevention. Antibiotic Resistance Questions and Answers. Accessed at,of%20those%20germs%20and%20their%20mechanisms%20of%20resistance.

15. Hospital & Healthcare Management. What Responsibilities Do Health Care Professionals Have in Preventing Antibiotic Resistance? Accessed at

16. Gerber JS. Antibiotic Stewardship Policy Offers Strategies for Inpatient, Outpatient Pediatrics. AAP News, December 28, 2020. Accessed at

17. Centers for Disease Control and Prevention. Be Antibiotics Aware Partner Toolkit. Accessed at

Ronale Tucker Rhodes, MS
Ronale Tucker Rhodes, MS, is the Senior Editor-in-Chief of BioSupply Trends Quarterly magazine.