High-Yield Katzung Pharmacology: Tetracyclines & 30S Protein Synthesis Inhibitors

Protein synthesis inhibitors:

 Bacterial ribosome is composed of 50S and 30S subunits
 30S drugs are aminoglycosides and tetracyclines
 50S drugs are macrolides, lincosamides, chloramphenicol and
oxazolidinones

According to spectrum:
1. Broad
a. Chloramphenicol
b. Tetracyclines
2. Moderate
a. Macrolides
b. Aminoglycosides
c. Ketolide
3. Narrow:
a. Lincosamides
b. Oxazolidinones
Tetracyclines are broad spectrum bacteriostatic antibiotics that inhibit
protein synthesis
Structure:
 4 fused rings with conjugated double bonds

MOA:
 Bind to A site of 30S subunit
 Prevent tRNA binding on A site
 Protein synthesis inhibited
 Bacteriostatic

Tetracyclines:
 Broad spectrum antibiotics
 Gram positive, gram negative bacteria
 Particularly species of
 rickettsia (gm -ve)
 Chlamydia
 Mycoplasma
Clinical use:
1. Primary use
a. Treatment of infections caused by
i. Mycoplasma in adults