Myths and Facts: Antibiotics

The discovery of antibiotics is one of the biggest successes of modern medicine, and they are among the most frequently prescribed medications.¹ The first antibiotic, penicillin, was discovered accidentally in a mold culture in 1928 by bacteriologist Alexander Fleming. And, while he noted it might someday have therapeutic value, penicillin wasn’t used until the 1940s when pathologist Howard Florey and chemist Ernst Chain isolated the active ingredient and developed a powdery form of the medicine. Also in the 1940s and 1950s, biochemist and microbiologist Selman Waksman, who coined the term “antibiotics” in 1942 and is now known as the father of antibiotics, isolated a number of other new antibiotics, including streptomycin, chloramphenicol and tetracycline.² Today, there are more than 100 different antibiotics available to doctors to cure both minor discomforts, as well as life-threatening infections.¹ But there are many misconceptions behind these once-called “miracle drugs.”

Separating Myth from Fact

Myth: Antibiotics can cure almost all illnesses, including the common cold.

Fact: Antibiotics only work to treat bacterial infections. They are useless to treat viral (e.g., colds) or fungal (e.g., ringworm) infections.¹ While some fungi and parasites may be susceptible to certain antibiotics, there are antifungals and antiparasitic agents for their treatment.³

Myth: All types of antibiotics are pretty much the same.

Fact: All antibiotics are not equal. There are seven main classes of antibiotics, which comprise more than 100 antibiotics, most of which have two names: a trade or brand name created by the drug company that manufactures the drug, and a generic name based on the antibiotic’s chemical structure or chemical class. Which type of antibiotic an individual needs depends upon many factors. However, the main factor is whether the type best combats the kind of bacteria causing the infection. For instance, only certain antibiotics will kill bacteria that cause ear infections. Other factors include medication cost, dosing schedule, common side effects, as well as allergic reactions. If a person has allergies, an entire class of antibiotics may have to be eliminated from consideration.

While the type of antibiotic needed is usually determined by a doctor, lab tests and cultures also may help to narrow down which species of bacteria is causing the infection.¹

Myth: It’s easy for doctors to diagnose when an illness requires treatment with antibiotics.

Fact: A bacterial infection is often difficult to diagnose, but there are some common signs that may be indicative of a bacterial infection. For instance, pneumonia may be detected by a persistent cough, stomachache or difficulty breathing. And, sepsis (bacteria in the blood) and bacterial meningitis (bacterial infection in the lining of the brain and spinal cord) may present with a stiff neck or changes in mental status.

There are some symptoms of a bacterial infection that occur as a result of a secondary infection. These include symptoms persisting longer than the expected 10 to 14 days a virus tends to last; a fever higher than one might typically expect from a virus; and a fever that gets worse a few days into the illness rather than improving. Sinusitis, ear infections and pneumonias are common examples of secondary infections.

Other than these, it is difficult to determine if an infection is bacterial without conducting tests. Tests that are frequently performed to diagnose a bacterial infection include a complete blood count and fluid cultures, such as a blood culture, urine culture or spinal culture (which requires a spinal tap).⁴

Myth: Antibiotics can be taken as a preventive measure to protect against some infections.

Fact: There are rare circumstances when antibiotic prophylaxis is recommended, such as pneumocystis pneumonia prophylaxis in HIV patients and during dental and gastrointestinal procedures, when some patients could develop an invasive infection of the heart valves called subacute bacterial endocarditis (SBE). These patients include those who have implanted mechanical or tissue heart valves, abnormal heart valves, a congenital heart defect, Dacron or Teflon vascular grafts or patches over cardiac defects, mitral valve prolapse (only if there is significant leakage) and pacemakers.⁵ However, the American Heart Association recently changed its guidelines regarding which patients should take a precautionary antibiotic to prevent infection. This change was in response to a growing body of scientific evidence that shows, for most people, the risks of taking prophylaxis antibiotics for certain procedures outweigh the benefits. These guidelines also are endorsed by the American Dental Association.⁶

Myth: There are few, if any, side effects from antibiotics.

Fact: Antibiotics frequently have side effects. Some of the more common are soft stools or diarrhea and a mild upset stomach. Others that a doctor should be notified about include vomiting, severe watery diarrhea and abdominal cramps, vaginal itching or discharge and white patches on the tongue.¹

Myth: Many people are allergic to antibiotics.

Fact: Some people are allergic to antibiotics, most commonly penicillin. In fact, about 10 percent of people report having an allergy to penicillin. However, most people who believe they are allergic can take penicillin without a problem, either because they wrongly identified a side effect as an allergy, meaning they were never truly allergic, or their allergy resolved over time.

Distinguishing between nonallergic reactions and true allergic reactions is important. Those who are allergic are typically treated with a less effective or more toxic antibiotic, which can lead to antibiotic failure or resistance. Therefore, those who believe they are allergic should provide as much detail to their physicians as possible about the reaction.

Allergic reactions occur when the immune system begins to recognize a drug as something foreign. True allergic reactions include rashes, such as hives (raised, intensely itchy spots that come and go over hours) and flat, blotchy rashes that spread over days but do not change by the hour; angioedema (swelling of the tissue under the skin, commonly around the face); throat tightness; wheezing; coughing; trouble breathing from asthma-like reactions; and anaphylaxis, a life-threatening allergic reaction that presents with symptoms of low blood pressure, difficulty breathing, abdominal pain, swelling of the throat or tongue and/or diarrhea or vomiting.⁷

Myth: A prescribing regimen is unnecessary to follow as long as the antibiotics are taken.

Fact: Taking antibiotics incorrectly can affect their absorption, which can reduce or eliminate their effectiveness.It’s important to know how many pills to take and how often to take them. In addition, some antibiotics need to be taken with something in the stomach, such as a glass of milk or some crackers, while others need to be taken only with water. Antibiotics also must be stored properly. Many children’s antibiotics need to be refrigerated, while others are best left at room temperature.¹

Myth: Once a person begins to feel better, the course of antibiotics can be discontinued.

Fact: Following through and taking the entire course of antibiotics is important for healing. If treatment is stopped midcourse, the bacteria may be only partially treated and not completely killed, allowing them to become resistant to the antibiotic and cause reinfection.¹

Myth: Antibiotics rarely interfere with other medications.

Fact: Antibiotics can have interactions with other prescription and nonprescription medications. Some examples include the antibiotic Biaxin, which should not be taken with Reglan, a digestive system drug; the antibiotics Flagyl and Protostat (metronidazole), which can cause problems when taken with the blood thinner Coumadin; and macrolide antibiotics, such as clarithromycin, erythromycin and azithromycin, which can boost blood levels of the antihistamine Hismanal (astemizole) to dangerous — and potentially lethal — levels.^1,8

Antibiotics also can often alter the way other drugs are metabolized. For instance, it is well-documented that the antibiotic erythromycin can make birth control pills less effective.⁹ Therefore, it is important for patients to tell their doctors and pharmacists which other medications they are taking before being prescribed an antibiotic.

Myth: Alcohol should never be consumed when taking antibiotics.

Fact: Many people believe that drinking alcohol while on antibiotic therapy can negate the effects of antibiotics. But, there are only three known interactions between alcohol and antibiotics: Isoniazid, which is used for treating tuberculosis, can interact with alcohol and cause toxic liver effects, so while on isoniazid, it is suggested to strictly stay away from alcohol. Erythromycin antibiotic can enhance alcohol absorption from the gut, thereby causing reddening of the skin. Metronidazole, which is prescribed for the treatment of female reproductive organ and oral infection, also is known to interact with alcohol and induce vomiting and nausea. Other than these scenarios, it is generally considered safe to consume alcohol within moderation while on antibiotics. Too much alcohol intake, however, directly interrupts the liver metabolism and can mar the breakdown and excretion of medications, including antibiotics.¹⁰

Myth: Antibiotics can’t harm people.

Fact: People can be harmed by misusing antibiotics. Each day, 190 million doses of antibiotics are administered, 133 million of which are prescribed to nonhospitalized patients. Of these latter prescriptions, 50 percent are unnecessary because they are prescribed for colds, coughs and other viral infections. This can result in antibiotic resistance, which is a worldwide health problem that continues to grow.¹¹

Antibiotic resistance occurs when strains of bacteria in the human body become resistant to antibiotics due to use and abuse of antibiotics.¹¹ As a result of these antimicrobial-resistant organisms, many infectious diseases are increasingly difficult to treat, including HIV infection, staphylococcal infection, tuberculosis, influenza, gonorrhea, candida infection and malaria. Between 5 percent and 10 percent of all hospital patients develop an infection from antimicrobial-resistant organisms, 90,000 of whom die each year as a result of their infection, which is up from 13,300 patient deaths in 1992.¹²

Dispelling the Myths Now

Many patients ask or expect doctors to prescribe antibiotics when they feel sick. And, more often than not, doctors give in to patients’ requests, even when patients are not sick with a bacterial infection — the only type of infection antibiotics can treat. In addition, patients often don’t follow the prescribed treatment for antibiotics. Both physicians and patients must do their part to decrease the misuse of antibiotics, and that can begin by dispelling the myths about these miracle drugs.