Generic Name: gentamicin (gen tah MY sin)
Brand Names: Garamycin
Gentamicin is an antibiotic particularly effective in treating severe infection cause by a wide variety of gram negative bacteria. It belongs to a class of drugs known as aminoglycoside antibiotics.
Destroys gram-negative bacteria by irreversibly binding to subunit of bacterial ribosomes and inhibiting protein synthesis, the amino acid incorporation into the growing protein chain is blocked by the drug, lowering the protein manufactured resulting in misreading of genetic code and separation of ribosomes from messenger RNA leading to incorrect production of proteins.
Example of gram negative:
Pseudomonas aeruginosa, Escherichia coli, and Proteus, Klebsiella, Serratia, Enterobacter, Citrobacter, or Staphylococcus species
Inspite of the effectiveness of the drug, increasig concern was raised about its toxicity particularly its effect in the kidney.
Administration is via: intravenous and intravascular
% bound to protein: < 10 %
Time to reach the peak plasma level: 1-1.5 hr (intramuscular) and 30 mins.(intravenous)
Plasma half life: 2 hours
Excretion in urine: 90% parent drug
Active metabolites: no
Therapeutic range (µg/ml): 4-8 (peak)
Toxic range (µg/ml): > 12 (peak), >2(trough)
RIA or enzyme - linked immuno assay
>Sample collection requires careful attention to number of parameters.
>It should not be collected using heparin as an anticoagulant because it provides undefined interference with the assay.
>Peak level are obtained at the appropriate time determined by the administration protocol.
>trough sample should be collected 30 mins. Or less prior to the next dose
>both peak and trough should be obtained for most efficient monitoring of aminoglycoside.
REFERENCE: CLINICAL CHEMISTRY BY: DONALD CALBREATH