What is the Difference Between Prophylactic and Therapeutic Antibiotics

The main difference between prophylactic and therapeutic antibiotics is that prophylactic antibiotics decrease the chance of infection, whereas therapeutic antibiotics treat bacterial infections.  

Prophylactic and therapeutic antibiotics are two types of antibiotics that prevent bacterial infections. Generally, antibiotics work by killing bacteria or preventing them from spreading.

Key Areas Covered

1. What are Prophylactic Antibiotics
   • Definition, Characteristics, Importance
2. What are Therapeutic Antibiotics
   • Definition, Characteristics, Importance
3. Similarities Between Waterborne and Vector Borne Diseases
   • Outline of Common Features
4. Difference Between Waterborne and Vector Borne Diseases
   • Comparison of Key Differences

Key Terms

Antibiotics, Prophylactic Antibiotics, Therapeutic Antibiotics

What are Prophylactic Antibiotics

Prophylactic antibiotics are the antibiotics given prior to surgery or dental procedure to prevent bacterial infections. This practice is also known as antibiotic prophylaxis and it is not a widespread practice due to several reasons. These reasons include the increase of resistance of bacteria to antibiotics, the change of bacteria that cause infections, and the improvement of technology to detect infections. However, this practice is important in use for individuals who have certain risk factors for bacterial infections. Some of them are surgeries for head and neck cancer, gastrointestinal surgeries, cesarean delivery, surgeries for implanting devices, and cardiac procedures such as coronary artery bypass grafts.

Figure 1: Cephalexin

The common antibiotics used in surgeries are cephalosporins, such as cefazolin and cefuroxime. Amoxicillin or ampicillin is important in dental procedures. Furthermore, the risk factors of bacterial infections include very young or very old age, poor nutrition, obesity, diabetes, smoking, existing infection (even at a different site, away from the surgery site), recent surgery, extended hospital stay before the procedure, and certain congenital heart conditions (ones that exist since birth).

What are Therapeutic Antibiotics

Therapeutic antibiotics are the antibiotics given after a bacterial infection. Therefore, this type of antibiotic is important in the treatment and prevention of bacterial infections. In general, the main function of antibiotics is either to kill or prevent the growth of bacteria. Usually, empiric therapy is important when a bacterial infection causes an illness, but the responsible pathogen has not been identified. This therapy involves the use of broad-spectrum antibiotics according to the signs and symptoms of the bacterial disease.

Figure 2: Therapeutic Antibiotics

Moreover, definitive therapy is used when the infectious agent is identified. It involves the use of narrow-spectrum antibiotics. Sometimes, the type of antibiotics depends on their cost. More importantly, the identification of the bacterium that causes the bacterial infection is critical in reducing the cost and the toxicity of antibiotic therapy. It is also important in the emergence of antimicrobial resistance to antibiotics. Normally, antibiotics are important as a preventive measure in individuals with risk factors such as weakened immune systems, taking immunosuppressive drugs, cancer, and surgery.

Similarities Between Prophylactic and Therapeutic Antibiotics

• Prophylactic and therapeutic antibiotics are two types of substances that prevent bacterial infections.
• Usually, antibiotics can either kill bacteria or prevent bacterial growth.
• Both types of antibiotics are important for individuals at high risk for bacterial infections.

Difference Between Prophylactic and Therapeutic Antibiotics

Definition

Prophylactic antibiotics refer to the antibiotics given prior to a surgical incision while therapeutic antibiotics refer to medicines that inhibit the growth of or destroy bacteria.

Significance

Prophylactic antibiotics are given before the occurrence of a bacterial infection while therapeutic antibiotics are given after the occurrence of a bacterial infection.

Examples

Some examples of prophylactic antibiotics include cephalosporins, such as cefazolin and cefuroxime, and amoxicillin while some examples of therapeutic antibiotics include ciprofloxacin, nitrofurantoin, Mucinex, and azithromycin.

Conclusion

In brief, Prophylactic antibiotics are a type of antibiotic patients use prior to bacterial infections. Generally, individuals at high risk for bacterial infections take prophylactic antibiotics, for example, patients before surgeries. Therapeutic antibiotics, on the other hand, are important after a bacterial infection. Normally, antibiotics either kill or prevent the growth of bacteria. Moreover, therapeutic antibiotics can be either broad-spectrum or narrow-spectrum. However, the main difference between prophylactic and therapeutic antibiotics is their usage.

References:

1. Leekha S, Terrell CL, Edson RS. General principles of antimicrobial therapy. Mayo Clin Proc. 2011 Feb;86(2):156-67. doi: 10.4065/mcp.2010.0639. PMID: 21282489; PMCID: PMC3031442.

Image Courtesy:

1. “A course of green cefalexin pills” By Sage Ross – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Antibiotic Drugs ” By Global Panorama – Own Work (CC BY-SA 2.0) via flickr