Indication |
For treatment of infections where one or more of the following are the known or suspected pathogens: E. coli, Proteus species (both indole-positive and indole-negative), E. aerogenes, K. pneumoniae, S. marcescens, and Acinetobacter species. |
Pharmacodynamics |
Kanamycin is an aminoglycoside antibiotic. Aminoglycosides work
by binding to the bacterial 30S ribosomal subunit, causing misreading of
t-RNA, leaving the bacterium unable to synthesize proteins vital to its
growth. Aminoglycosides are useful primarily in infections involving
aerobic, Gram-negative bacteria, such as Pseudomonas, Acinetobacter, and
Enterobacter. In addition, some mycobacteria, including the bacteria
that cause tuberculosis, are susceptible to aminoglycosides. Infections
caused by Gram-positive bacteria can also be treated with
aminoglycosides, but other types of antibiotics are more potent and less
damaging to the host. In the past the aminoglycosides have been used in
conjunction with penicillin-related antibiotics in streptococcal
infections for their synergistic effects, particularly in endocarditis.
Aminoglycosides are mostly ineffective against anaerobic bacteria, fungi
and viruses. |
Mechanism of action |
Aminoglycosides like kanamycin "irreversibly" bind to specific
30S-subunit proteins and 16S rRNA. Specifically Kanamycin binds to four
nucleotides of 16S rRNA and a single amino acid of protein S12. This
interferes with decoding site in the vicinity of nucleotide 1400 in 16S
rRNA of 30S subunit. This region interacts with the wobble base in the
anticodon of tRNA. This leads to interference with the initiation
complex, misreading of mRNA so incorrect amino acids are inserted into
the polypeptide leading to nonfunctional or toxic peptides and the
breakup of polysomes into nonfunctional monosomes. |
Absorption |
Kanamycin is rapidly absorbed after intramuscular injection and
peak serum levels are generally reached within approximately one hour.
Poor oral and topical absorption except with severe skin damage. |
Volume of distribution |
Not Available |
Protein binding |
Not Available |
Metabolism |
Not Available |
Route of elimination |
Not Available |
Half life |
2.5 hours |
Clearance |
Not Available |
Toxicity |
Mild and reversible nephrotoxicity may be observed in 5 - 25% of
patients. Amikacin accumulates in proximal renal tubular cells. Tubular
cell regeneration occurs despite continued drug exposure. Toxicity
usually occurs several days following initiation of therapy. May cause
irreversible ototoxicity. Otoxocity appears to be correlated to
cumulative lifetime exposure. Drug accumulation in the endolymph and
perilymph of the inner ear causes irreversible damage to hair cells of
the cochlea or summit of ampullar cristae in the vestibular complex.
High frequency hearing is lost first with progression leading to loss of
low frequency hearing. Further toxicity may lead to retrograde
degeneration of the 8th cranial (vestibulocochlear) nerve. Vestibular
toxicity may cause vertigo, nausea, vomiting, dizziness and loss of
balance.
Oral LD50 is 17500 mg/kg in mice, over 4 g/kg in rats, and over 3 g/kg
in rabbits. |