10 Classes of Antibiotics You Should be Aware About

In the last two years, apart from the word ‘vaccine’, probably the only word that could’ve been more frequently used is ‘antibiotics’. The Covid-19 pandemic has once again demonstrated the utility of antibiotics and the extremely crucial role they play in today’s world. It may be surprising to many, but antimicrobial drugs have been used since ancient times. Archeological and anthropological experts have found that the big four ancient civilizations- Indus Valley, China, Mesopotamia, Egypt- had regular usage of different kinds of antimicrobial drugs to treat their diseased populations. However, the widespread use of these drugs in the modern times is attributed to two entities- John Parkinson who was the first documented person to use antibiotics for treating infections and Alexander Fleming who discovered penicillin, which was extensively used during the wartime to treat the injured.

Classes of Antibiotics

Antibiotics are a type of antimicrobial medicines that are used to treat various infections. There are over hundreds of antimicrobial drugs available today in the global antibiotics market. However, all these antimicrobial drugs are classified into certain classes according to their chemical and pharmacologic features, thus making them effective against a specific infection. These classes of antibiotics are mentioned here:

1. Penicillin

Among the first drugs to be used against infections, penicillins are group of beta-lactam antibiotics. Penicillins are further divided into five subclasses and most of them are synthesized by extracting naturally-occurring penicillins. Penicillins have proven to be extremely effective against pneumonia, meningitis, endocarditis, empyema, etc.

2. Tetracycline

One of the cheapest antimicrobial drugs present today, tetracyclines are a class of antibiotics obtained from various species of Streptomyces bacteria. Tetracyclines have a unique functionality as they act as growth inhibitors rather than killers of the infection-causing microbes. Tetracyclines are used to treat intestinal tract infections, sexually transmitted diseases, acne, urinary tract infections, etc.

3. Cephalosporin

Obtained from the Acremonium fungus, cephalosporins are a class of beta-lactam antimicrobial drugs. Cephalosporins are bactericidal in nature and are used to treat various infections like meningitis, lung infections, ear infections, urinary tract infections, etc.

4. Fluoroquinolone

Fluoroquinolones have synthetic origin and are bactericidal in nature. They are extremely effective antimicrobial drugs and feature in both human and veterinary medicine due to their ability to treat broad-spectrum infections. However, in case of humans, these drugs are recommended only for adults and that too when other antimicrobial drugs have failed in curing the patient.

5. Lincomycin

Bactericidal in nature, lincomycins are effective against gram-positive aerobes and anaerobes, along with certain specific gram-negative anaerobes. They are typically used to treat lower respiratory tract infections. However, due to their side-effects and toxicity, lincomycins are used only for those patients who are allergic to penicillins.

6. Macrolide

Obtained naturally, macrolides are protein synthesis inhibitors. Thus, they are similar to tetracyclines, in that, they inhibit the growth of infection-causing bacteria rather than killing them. They are highly effective against gram-positive and gram-negative bacteria and are used to treat certain respiratory tract infections.

7. Sulfonamide

Sulfonamides hold a unique place in the history of development of antibiotics as they were the first systematically used antibacterial drugs. Obtained synthetically, sulfonamides have slowly been pushed out of regular usage due to the high percentage of allergies associated with them. Nonetheless, sulfonamides have been of great help in treating infections like pneumocystis pneumonia, urinary tract infections, etc.

8. Glycopeptide Antibiotics

Derived from microbes, glycopeptide antibiotics are mainly used to treat those patients who are hypersensitive of beta-lactam antimicrobial drugs. Glycopeptide antimicrobial drugs are used to treat enterococcal infections, diarrhea, etc.

9. Aminoglycoside

Highly effective against gram-negative bacteria, aminoglycosides are derived from Streptomyces bacteria. However, aminoglycosides have been known to show some kind of nephrotoxicity and ototoxicity in certain cases which is why they are used to treat specific medical conditions only.

10. Carbapenem

Mostly used to treat bacterial infections, carbapenems are highly effective against intra-abdominal infections, urinary tract infections, bloodstream infections, etc. Carbapenems are often considered as the last line of defense against treating bacterial infections and are used to cure multidrug-resistant infections.

The Bottom Line

The ten classes of antibiotics mentioned above cover almost all the available antimicrobial drugs available in the world today. Their efficacy in treating microbial infections is unmatched. However, overuse and frequent administration of these drugs have given rise to what is known as antimicrobial resistance wherein the infection-causing bacteria evolve mechanisms to resist the effect of antibiotics. Doctors and medical experts around the world, as a result, have been staunchly advocating against the unchecked and unrestrained use of antibiotics.

About the Author(s)

Akhilesh Prabhugaonkar

Akhilesh Prabhugaonkar holds a bachelor’s degree in Electronics Engineering from the reputed Vishwakarma Institute of Technology. He has a special interest in the field of forensics, world history, international relations and foreign policy, sports, agriculture, astronomy, security and oceanography. An ardent bibliophile and melophile, Akhilesh loves to write on topics of his interest and various other societal issues. This love for writing made him enter the professional world of content writing and pursue his career in this direction.