Antibiotics for Treating Infections

Have you ever wondered what antibiotics are? Have you ever wondered how they work?

These “miracle drugs” were an important breakthrough of the 20th century, helping many more people live due to fewer deaths from infectious diseases. There are, however, misconceptions about antibiotics.

Scientist illustrating antibiotic chemical formula with a marker on a clear screen facing the camera
Andrew Brookes / Getty Images

One common misconception is that you should take antibiotics until you feel better. Many people wrongly believe they can stop antibiotics when they feel better, even if their healthcare provider had asked them to take the antibiotic for longer.

Did you know that by not following healthcare providers’ orders on antibiotic prescriptions, you could end up with even greater health problems than what you began with? This is because there are now bacteria that resist antibiotics.

These are called antibiotic-resistant bacteria because the drugs no longer stop these bacteria—or don’t stop them quickly enough. This is very dangerous for us all, and it can be scary.

It is important that everyone understands how antibiotics work. This can be done by clearing up any misconceptions about antibiotics. If we let these misconceptions continue, many people can get sick from drug-resistant bacteria, and there may not be drugs to treat these bacteria.

Listed below are several important points to consider before starting any antibiotic treatment.

What Are Antibiotics?

Antibiotics are medications that kill or stop the growth of bacteria. They do this by blocking important functions within the bacteria cell.

There are many types of antibiotics, including topical over-the-counter antibiotic creams and ointments that you spread over your skin, pills that you swallow, liquid for kids to swallow, and intravenous solutions that are injected into your vein.

These drugs stop minor bacterial infections, as well as life-threatening system-wide infections, and each antibiotic kills different groups of bacteria.

Early antibiotics were discovered and isolated from molds. Molds can be dangerous: Many infections are caused by molds and different types of fungi. In this case, though, molds were very useful.

These antibiotic molecules were produced by the molds to be used as a defense against bacteria. We “stole” these from the molds and started to treat infections with them.

More recently, newer classes of antibiotics have been created in laboratories. Because the targets of antibiotics are often specific to bacterial rather than human cells, they generally have few side effects and are considered safe for the vast majority of people.

Side Effects

While antibiotics are safe for most people, a small number of people are prone to allergic reactions. These allergic reactions can be to penicillin or other antibiotics (like Bactrim or Cotrim). Symptoms include rash, throat tightening or swelling, difficulty breathing, swollen lips, a rash or hives, gastrointestinal problems, light-headedness, loss of consciousness, and low blood pressure.

In rare cases, people can die from allergies. If you suspect you have an allergy to an antibiotic, immediately stop using it and contact your physician or healthcare provider.

Other common side effects of antibiotics may include diarrhea and yeast infections. These occur because antibiotics can affect the natural balance of the bacteria that are part of our microbiome.

Many studies have looked at how to preserve or replace good bacteria, and a few have shown that probiotics can help with anything other than C. difficile. However, further research needs to be done in this area.

Antibiotics can interfere with birth control and decrease efficacy, so it’s important to talk to your healthcare provider before taking them if you are on birth control.

Drug resistance can also develop. This can happen when people take antibiotics “just in case”—like when they are traveling and develop a bit of diarrhea, but are not sick. It can also happen when drug use isn’t monitored when people have to take antibiotics for a long time.

The resistances that develop may initially be found in hospitals, but later spread out into the community. The result can be antibiotic resistances accumulating that we don’t have good antibiotics to treat.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Gaynes R. The discovery of penicillin—new insights after more than 75 years of clinical useEmerg Infect Dis. 2017;23(5):849-853. doi:10.3201/eid2305.161556

  3. Olsufyeva EN, Yankovskaya VS. Main trends in the design of semi-synthetic antibiotics of a new generationRuss Chem Rev. 2020;89(3):339-378. doi:10.1070/RCR4892

  4. Maker JH, Stroup CM, Huang V, James SF. Antibiotic hypersensitivity mechanismsPharmacy (Basel). 2019;7(3):122. Published 2019 Aug 27. doi:10.3390/pharmacy7030122

  5. CDC. Antibiotics aren't always the answer.

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  7. WHO. Antibiotic resistance.

Additional Reading

By Ingrid Koo, PhD
 Ingrid Koo, PhD, is a medical and science writer who specializes in clinical trial reporting