Antibiotics Classification:
Antibiotics are classified in a number of ways, including:
โBy their mechanism of action: This is the most important way to classify
antibiotics, as it determines which bacteria they are effective against. Antibiotics
can be classified into the following groups based on their mechanism of action:
a. Cell wall synthesis inhibitors: These antibiotics prevent the bacteria
from forming a rigid cell wall, which is essential for their survival.
Examples of cell wall synthesis inhibitors include penicillins,
cephalosporins, and vancomycin.
b. Protein synthesis inhibitors: These antibiotics interfere with the
bacteria's ability to make proteins, which are essential for their growth and
reproduction. Examples of protein synthesis inhibitors include
aminoglycosides, tetracyclines, and macrolides.
c. Nucleic acid synthesis inhibitors: These antibiotics interfere with the
bacteria's ability to make DNA or RNA, which are essential for their
genetic material. Examples of nucleic acid synthesis inhibitors include
fluoroquinolones and rifampicin.
โBy their spectrum of activity: This refers to the range of bacteria that an
antibiotic is effective against. Antibiotics can be classified as narrow-spectrum,
broad-spectrum, or extended-spectrum agents.
a. Narrow-spectrum antibiotics: These antibiotics are effective against a
limited number of bacteria. Examples of narrow-spectrum antibiotics
include penicillin G and erythromycin.
b. Broad-spectrum antibiotics: These antibiotics are effective against a
wide range of bacteria. Examples of broad-spectrum antibiotics include
amoxicillin and cefuroxime.
c. Extended-spectrum antibiotics: These antibiotics are effective against
even more bacteria, including some that are resistant to other antibiotics.
Examples of extended-spectrum antibiotics include ciprofloxacin and
piperacillin/tazobactam.
โBy their chemical structure: Antibiotics can also be classified according to their
chemical structure. This can be helpful in understanding how they work and how
they interact with other drugs.
The most common classes of antibiotics are:
โPenicillins: Penicillins are the oldest and most widely used class of antibiotics.
They are effective against a wide range of gram-positive bacteria, including
Streptococcus pneumoniae, Staphylococcus aureus, and Enterococcus faecalis.
โCephalosporins: Cephalosporins are similar to penicillins, but they are more
resistant to beta-lactamase enzymes, which are produced by some bacteria to
break down penicillins. Cephalosporins are effective against a wide range of
gram-positive and gram-negative bacteria.
