Protein Synthesis Inhibitors (Aminoglycosides ) Flashcards
What are aminoglycosides ?
1) Amikacin
2) Gentamicin
3) Neomycin
4) Streptomycin
5)Tobramycin
MOA of aminoglycosides :
A) Binding to the 30S ribosomal subunit , interfering with assembly of the functional ribosomal apparatus
B) Cause the 30S subunit of the completed ribosome to misread the genetic code
Antibacterial spectrum of aminoglycosides :
Effective against gram negative bacilli ( including multi-drug resistant P.aeruginosa )
Aminoglycosides are ………….. & ………………
Bactericidal , Concentrations-dependant
Synergy of aminoglycosides:
Aminoglycosides are added with B-lactams
MOR of aminoglycosides :
1) efflux pumps
2) Decreased uptake
3) Modification and inactivation of the drug by plasmid-associated synthesis of enzymes that hydrolyse aminoglycosides
One of the aminoglycosides that is less vulnerable to plasmid-associated enzymes :
Amikacin
Administration of aminoglycosides :
All are given IV
The aminoglycoside that is NOT given IV
Neomycin
Distribution of aminoglycosides :
- Variable distribution in body fluids but in CSF it is inadequate distributed
- Cross the Placenta
Elemination of aminoglycosides :
90% are excreted unchanged in urine
Meaning that accumulation occurs in cases of renal dysfunction
Adverse effects of Aminoglycosides:
1) Ototoxicity
2) Nephrotoxicity
3) Neuromuscular paralysis
4) Allergic reaction
Ototoxicity and aminoglycosides :
1) Might cause irreversible deafness (Vestibular and auditory )
2) Vertigo ( Especially with streptomycin )
Nephrotoxicity with aminoglycosides :
1) disrupt Ca++ - mediated transport processes
2) Mild reversible renal impairment to irreversible acute tubular necrosis
Neuromuscular Paralysis and aminoglycosides :
Patient with myasthenia gravi are at risk
