Protein Synthesis Inhibitors (Aminoglycosides) Flashcards
List the aminoglycosides.
- Amikacin (parenteral).
- Gentamicin (eye drop or OIU).
- Neomycin (topical; powder or ointment).
- Streptomycin (parenteral).
- Tobramycin (eye drop or ointment).
Are aminoglycosides bactericidal or bacteriostatic?
Bactericidal.
Aminoglycosides are used for…
Aerobic gram-negative bacilli infections.
What is the mechanism of action of aminoglycosides?
Diffuse through porins into the cytoplasm via oxygen-dependent active transport to bind to the 30S ribosomal subunit, thereby interfering with the assembly of the functional ribosomal apparatus and/or causing 30S subunit of the completed ribosome to misread the genetic code.
Aminoglycosides exhibit ____ dependent bactericidal activity and ___.
Concentration, PAE.
Aminoglycoside Antibacterial Spectrum
- Aerobic gram-negative bacilli (Incl: multi-drug resistant pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterbacter species).
- UTIs.
Aminoglycosides are used with ___ because of the synergistic effect against Gram-positive organisms.
Cell wall active drugs.
Resistance Mechanisms to Aminoglycosides
- Efflux pumps; impaired entry and decreased uptake.
- Enzymes (modification: transferase) OR (inactivation: adenylation, acetylation, or phosphorylation).
The aminoglycoside least effective to enzymatic inactivation is…
Amikacin.
Do aminoglycosides exhibit cross-resistance?
No.
Why are aminoglycosides given parenterally?
Because they are highly polar and polycationic.
Neomycin is given orally or topically because…
It is highly nephrotoxic when given parenterally.
NOTE: Other aminoglycosides are available topically.
Aminoglycosides for Pregnant Women?
Cross the placental barrier and accumulate in fetal plasma and amniotic fluid.
Aminoglycosides are hydrophobic. How does this affect their distribution?
Tissue concentrations may be subtherapeutic and penetration to most body tissues minimal.
How are aminoglycosides given for CNS infections?
Intrathecal or intraventricular route.
