Antibiotics (Protein Synthesis Inhibitors)
AT 30 CEL 50 Chloramphenicol
Aminoglycosides Azithromycin
Tetracycline Linezolid
Normal Bacterial Protein Synthesis
1. Initiation complex formed
2. Binding of tRNA to ribosome (30s)
3. Codon: Anticodon recognition
4. Peptide bond formation (50s)
5. Translocation (50s)
AMINOGLYCOSIDES
Streptomycin, Gentamycin, Tobramycin, Neomycin, Amikacin
These are irreversible bactericidal inhibitors. They move into cytoplasm by diffusion via porins in the
outer membrane and via active transport in the inner cell membrane.
MOA: 1. Inhibit formation of 30s initiation complex 2. Break polysomes into monosomes 3. Cause
mRNA misreading 4. Bind to membrane and destroy it (bactericidal)
Used parenterally for systemic and topically for skin or ocular infections.
*Show concentration dependent killing and post antibiotic effects*
SE include Nephrotoxicity, Ototoxicity and Allergy. This drug can cause NMJ block so not given to
patients with Myasthenia Gravis.
Spectrum: Only aerobic bacteria. Streptomycin: TB, Plague. Gentamycin: Gram negative action on
Staph, Strep and Entero. Tobramycin: same as Gentamycin but more effective against Pseudomonas.
Amikacin: Used against Genta and Tobramycin resistant strains. Neomycin used topically and also to
prepare bowel before surgery.
TETRACYCLINES
Short Acting: Tetracycline, Oxytetracycline, Chlortetracycline
Intermediate Acting: Methacycline
Long Acting: Doxycycline, Minocycline and its derivative Tigecycline (more 30s affinity and less
resistance susceptibility)
MOA: Binds to 30s subunit preventing binding of tRNA to acceptor site
AT 30 CEL 50 Chloramphenicol
Aminoglycosides Azithromycin
Tetracycline Linezolid
Normal Bacterial Protein Synthesis
1. Initiation complex formed
2. Binding of tRNA to ribosome (30s)
3. Codon: Anticodon recognition
4. Peptide bond formation (50s)
5. Translocation (50s)
AMINOGLYCOSIDES
Streptomycin, Gentamycin, Tobramycin, Neomycin, Amikacin
These are irreversible bactericidal inhibitors. They move into cytoplasm by diffusion via porins in the
outer membrane and via active transport in the inner cell membrane.
MOA: 1. Inhibit formation of 30s initiation complex 2. Break polysomes into monosomes 3. Cause
mRNA misreading 4. Bind to membrane and destroy it (bactericidal)
Used parenterally for systemic and topically for skin or ocular infections.
*Show concentration dependent killing and post antibiotic effects*
SE include Nephrotoxicity, Ototoxicity and Allergy. This drug can cause NMJ block so not given to
patients with Myasthenia Gravis.
Spectrum: Only aerobic bacteria. Streptomycin: TB, Plague. Gentamycin: Gram negative action on
Staph, Strep and Entero. Tobramycin: same as Gentamycin but more effective against Pseudomonas.
Amikacin: Used against Genta and Tobramycin resistant strains. Neomycin used topically and also to
prepare bowel before surgery.
TETRACYCLINES
Short Acting: Tetracycline, Oxytetracycline, Chlortetracycline
Intermediate Acting: Methacycline
Long Acting: Doxycycline, Minocycline and its derivative Tigecycline (more 30s affinity and less
resistance susceptibility)
MOA: Binds to 30s subunit preventing binding of tRNA to acceptor site
