Antimicrobials & Antibiotics


“Antimicrobial” is a general term refers to a group of drugs which treat a microbial infection includes antibiotics, antifungals, antiprotozoals, and antivirals. In this article, we are going to focus on antibiotics drugs which are more commonly used. Antibiotics are organic compounds produced by microorganisms or industry, their function is killing, limiting or stopping growth of microbes like: Bacteria, parasites and many another microorganisms except virus.


Antibiotics are grouped into classes based on different conditions which are shown in the below table. However, antibiotics within each class often affect the body differently and may be effective against different bacteria.

Classified According ToTypes
Mechanism of action– Inhibiting cell wall synthesize of microbes
(Ex. Cephalosporins)
– Injuring cell membrane (Ex. Daptomcin).
– Inhibiting nucleic acid synthesize
– Inhibiting protein synthesize of microbe
(Ex. Tetracyclines).
– Acting with cell metabolic pathway
(Ex. Trimethoprim+Sulfamethoxazole)
Spectrum of actionNarrow-spectrum antibiotics:
The target of them is specific to
Gram negative only or Gram positive.
Broad-spectrum antibiotics: Act on wide
range of microbe.
Mode of actionBactericidal: Kills the bacteria
(Ex. Carbapenems, Cephalosporins).
Bacteriostatic: Can stop or slow
growth of bacteria (Ex. Tetracyclines).
Chemical structuresTetracyclines.

Side effects of antibiotics:

Vomiting,Wheezing,Anxiety,Nausea,Diarrhoea,Lose of appetite, Coughing, And etc.

Antibiotic resistance:

It’s a situation when a bacterium can no longer be killed by antibiotic that is designed for it, so it continous to replicate and develop, therefore the doctor should develop another new antibiotic to kill the microbe. Resistance occurs when a bacterium starts to change its DNA or by mutation which can turn the bacterium into a new one for the antibiotic so it can’t kill it. Causes include: Misusing them, using them without doctor’s advice. One of the best solutions to this problem is never using antibiotics unless it’s necessary.